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2019年2月23日托福听说读写真题答案回忆蹲点汇总+解析
回忆1：
阅读部分
1.原始大气层与生命的形成
2.沙漠里动物和植物的生活
3.19世纪的印象派艺术
4.工业化对labor system的影响
5.鸟类歌唱
6.森林数量的变化对大平原的影响
7.石化的珊瑚地区对zooxanthellae的证据
8.farming improvement分别在中国，欧洲的发展
9.恐龙parental care
10.gliding
11.南亚昆虫翅膀
1.原始大气层与生命的形成
2.沙漠里动物和植物的生活
3.19世纪的印象派艺术
4.工业化对labor system的影响
5.鸟类歌唱
6.森林数量的变化对大平原的影响
7.石化的珊瑚地区对zooxanthellae的证据
8.farming improvement分别在中国，欧洲的发展
9.恐龙parental care
10.gliding
11.南亚昆虫翅膀
回忆2:
独立写作
Do you agree or disagree with the following statement? It is difficult for a teacher to be both popular (well-liked) and effective in helping students in learning.
参考思路：
观点：不同意，老师可以同时做到这两点。
理由段一：受欢迎的老师更能激发学生的学习兴趣，帮助他们有效学习。
理由段二：用好的方法教学既可以让老师受欢迎又能高效帮助学生学习。
让步段：同时做到这两点确实不容易，但是老师要慢慢培养这方面的意识，运用更好的教学方法丰富自己的教学风格，帮助学生有效地学习。
综合写作
重复2017年2月18号综合写作原题
土星的卫星Titan有3个unusual features 难以解释。
阅读
1.
unusual orbit 普通的卫星运转是circular环形的轨道,但是Titan卫星运转时是 elliptical orbit椭圆轨道。
2.
massive depression Titan表层周边有很多depression and crater洼地和坑，正常来讲，一般是由火山活动和碰撞造成的，但是没有证据显示周边有火山，碰撞的话也应在随机位置。
3.
Titan上沙丘的坡向与Titan所吹的风向相反。
听力反驳
1.Titan不是一个单一的卫星，周边的卫星群相互作用，相互影响，就使得它呈现椭圆形轨道。
2.洼地和坑不是火山和碰撞造成的，而是强降雨导致的。
3.关于沙丘的朝向。Titan上的沙子很重，一般的风吹不动。Titan每年会有几次风力很大的朝东吹的风暴storms，它的风力是平常风的十倍，可以将沙子往东吹。
回忆3：
口 语 部 分
Task 1
哪种背景的人领导政府比较好？law,military,business
Task 2
学校政策，Parents can know their students grades only when they get permisssion by their children?
Task 3
修复钟楼大钟的意见讨论。
Task 4
讲了passive defense。 一些动物用自己的信号来避免直接冲突。例如panda在树上留气味，别的熊猫闻到后为避免跟它发生斗争而走开。
Task 5
男同学的妈妈到学校开会，打算晚上和他一块吃晚饭。不过会议结束的早，所以下午的时间妈妈有空。这位同学下午有乐队排练，要么叫妈妈去看他的排练，然后晚上一块吃饭；要么自己不去乐队排练，叫人代替他。
Task 6
大城市人的返乡好处：住在大城市的人会把bus system带回乡下，也建设bus system。人口和经济给城市人带来的影响，城市人觉得hometown房价低。
回忆4：
听 力 部 分
Conversation（回忆较少、欢迎补充）
1.老师让学生看书写读后感，讨论书中的概念，问老师可不可以用这个概念
Lecture
1.考古
2.讲牛顿第三定律在航空方面的应用
3.B 和莫扎特 对现代音乐影响
4.渔业
5.fusion 核能
6.洞穴艺术，小孩的画
回忆5：
Reading
1.鸟类歌唱（很难）；重复2017年12月10日
2.讲原始大气层与生命的形成；
3.Archeology：Megafauna extinction 恐龙的亲代哺乳；
4.石化的珊瑚地区对zooxanthellae的证据；
5.Biology：Animal behavior(whether instinct or learn)
两种相对立的观点，两派人；
6.Agriculture in desert area(how to solve the problem)
解决水资源短缺的问题，说了好几种；
7.Biology：Plants and animals in dry evolve different ways to adapt to the environment.
8.farming improvement分别在中国、欧洲的发展；
9.原始大气层和现代大气层对比；
10.南亚昆虫翅膀；
11.沙漠里动物和植物的生活；
12.19世纪的印象派艺术；
13.森林数量的变化对大平原的影响；
14.工业化对labor system的影响
词汇题：（求补充）
robust=strong
attached = additional
adjacent
hastened
unmistakable
refuge
critically
initially
refuge
critically
initially
secrete=release
prompt
retarding=slowing
surge=increased demanding
dispersed
回忆6：
Listening
Conversation
1. 是关于学生想要换工作，以前restaurant的工作早班导致有时上课迟到，晚班的话一下课就要去上班等等最后推荐去申请student express的driver
2. 就是关于housing，在一个housing fair上学生来咨询，好像是她的朋友还没拿到学校的offer但是想等她朋友拿到再一起申请学校宿舍同一个room，但是申请是要一起申请并且申请里要写对方的名字才能同一个房间，最后学生表示先考虑自己，自己先申请这样
3. 女学生跟教育学教授讲去小学采访的经历,然后教授提出一些建议
4. 好像是讲theater, 女学生好像要和老师去重新整理film的资料,教授邀请女学生去干嘛忘记了,但是后来女学生又说哪里有一件大的空教室,然后教授就很开心的答应了
Lecture
1.渔业；
2.物理学,讲牛顿第三定律 在航空方面的应用；
3.讲fusion，核能；
4.洞穴艺术；
5.作家作品；
6.小孩的画。
回忆7：
独立写作
重复2018年4月21日/2016年12月11日
A/D: It is difficult for teachers to be both popular (well liked) and effectively in helping students’ study.
老师要做到popular和教学兼顾很难，你同意吗？
综合写作
重复2018年2月18日
Titan上有很多unexplained的features。
阅读部分：
1. unusal orbit
2. massive depressions
3. sand dunes
听力部分：反驳。
1. 因为Titan这个planets不是一个single moon，而是several small moons组成的 在他们不断collide，merge together 最终把他们的orbit从circular拉成了elliptical
2. massive depressions的形成和Earth差不多。在地球上，rocky objects会被水or liquids 给dissolved，所以只要Titan上有ranifall，就可以形成depressions
3. sand dunes（文章说他们往westward，但是风是eastward） 听力说，在titan上，风太弱了吹不动很重的这些dunes，而真正影响dunes movement的是hurricanes，hurricanes比wind强十倍，而hurricanes是blow westward的。
回忆8：
Speaking
Task 1
law,military,business.哪种背景的人领导政府比较好？
Task2
Do you agree or disagree? Parents can know their students grades only when they get permisssion by their children?
学校policy：在学校，家长未经允许不得看望孩子，是否同意？
Task3
阅读：学校想花钱来改善上学校钟塔上的 bell，因为钟塔是学校的象征，另外 bell 的声音还可以让学生知道时间。
听力：不同意。不要花钱在 improve bell 上，钟塔 tower 才是学校的象征，bell 不是。人们想到他们的学校时候就会想到学校的 tower，因为 tower 的形象在学校网站和校服上都有的。另外，学生都有手机看时间，不要钟塔来发出声音报时，把多的钱来买桌椅更好。
Task4
讲了passive defense。 一些动物用自己的信号来避免直接冲突。例如panda在树上留气味，别的熊猫闻到后为避免跟它发生斗争而走开。
Task5
男学生妈妈来开会，打算晚上一起吃饭，但会议结束早，所以妈妈下午有空，但是男生下午需要乐队排练，可以叫妈妈来看然后吃饭，或者skip，乐队排练找人代替。
Task 6
大城市人的返乡好处：住在大城市的人会把bus system带回乡下，也建设bus system。人口和经济给城市人带来的影响，城市人觉得hometown房价低。
回忆9：
综合写作
阅读主要观点提取:
土星最大的卫星Titan存在三个无法解释的不同寻常的特征。
第一，Titan的轨道是椭圆形elliptical而不是常规的圆形circular。
第二，Titan的两极地区存在洼地depressions。这些洼地既不是火山爆发形成的也不是陨石撞击形成的。
第三，Titan上沙丘的坡向与Titan所吹的风向相反。
听力主要观点提取:
最新的研究表明，Titan上的这些特征都可以有合理的解释。
第一，关于椭圆形的轨道。Titan并不是单一的卫星，而是多个卫星碰撞collide后合并merge在一起的。每次的碰撞，都会形成一定的冲击力impacts，这种冲击力就会改变轨道。随着时间的推移，轨道就变成椭圆形elliptical。
第二，关于洼地。Titan上洼地的形成类似于地球上的洞穴caves。由于Titan上有降雨rainfall，并且降雨集中在Titan的两极地区。所以Titan两级地区的岩石被雨水分解dissolve,形成depressions。
第三，关于沙丘的朝向。Titan上的沙子很重，一般的风吹不动。Titan每年会有几次风力很大的朝东吹的风暴storms，它的风力是平常风的十倍，可以将沙子往东吹。
The reading passage claims that there are three unusual features about Titan that cannot be explained, while the speaker thinks that each of the features has a reasonable explanation.
To begin with, the reading states that the orbit of the Titan is elliptical rather than circular, which is quite puzzling and abnormal. According to the lecture, however, this phenomenon is caused by the fact that Titan is originally not a single moon but the combination of several smaller moons, which compounds its orbit. The orbit is shifted by the force of each colliding slightly and becomes elliptical over time.
In addition, the author argues that the existence of depressions in Titan's polar areas is dubious, since they cannot be explained by volcanic activities or meteorite impact. The professor refutes this argument by pointing out that there are frequent rainfalls in Titan and it is those liquids that formed the multiple caves on Titan, as the case on earth.
Finally, contrary to the belief in the passage that the slope of the dunes on Titan is not in compliance with the force of the wind, the lecturer contends that the sand on the moon is so heavy that only those storm winds, ten times stronger than the usual wind, can determine the eastward slope of the dunes.
回忆10：
阅读
01
Early life-forms and Earth’s Atmosphere
原始生命与地球大气
重复2014.06.15
先讲了生物形成的条件，第一是离太阳的位置刚刚好；第二是先有bacteria，然后才有更加复杂的生物；原始的大气层是由一些methane和二氧化碳组成，温室气体，在当时太阳不是那么bright的时候（dim period）提供了一些热量，可以使早期生物生存；现在的地球是氢气和氧气主要组成，如果现在的大气层还和之前一样那么多methane和二氧化碳的话，地球会too hot for organisms to survive（这里考到一个题，早期和现在的大气区别）；然后又说到细菌产生的氧气可以阻挡UV（紫外线），为生物提供protection，而其他planet没有氧气，所以生物无法生存。
altered = transformed 改变
emitted = released 释放
retarding = slowing 迟滞，延迟
abundant = plentiful 大量的
sustain = support 支持
真题原文
Early life-forms and Earth’s Atmosphere
Why has life flourished on Earth? This question has a two-part answer. First, Earth has been a cradle for life because of its position relative to the Sun. second, once life began on Earth, simple early life-forms (photosynthetic bacteria) slowly but inexorably altered the environment in a manner that not only maintained life but also paved the way for later, complex life-forms. These changes allowed later organisms to evolve and thrive. Humans and other higher organisms owe their life-supporting environment to these early life-forms.
Earth’s earliest atmosphere contained several gases: hydrogen, water vapor, ammonia, nitrogen, methane, and carbon dioxide, but no oxygen. Gas mixtures emitted from present-day volcanoes resemble this early atmosphere, suggesting its origin from volcanic eruptions. In Earth’s earliest atmosphere, methane and carbon dioxide occurred at much higher levels than at present—a circumstance that was favorable for early life. Methane and carbon dioxide are greenhouse gases that warm atmospheres by retarding loss of heat to space. These two gases kept Earth warm during the Sun’s early history, when the Sun did not burn as brightly as it now does. (An early dim period, with later brightening, is normal for stars of our Sun’s type.)
Earth’s modern atmosphere, which is 78 percent nitrogen gas, 21 percent oxygen, and about 1 percent argon, water vapor, ozone, and carbon dioxide, differs dramatically from the earliest atmosphere just described. The modern atmosphere supports many forms of complex life that would not have been able to exist in Earth’s first atmosphere because the oxygen level was too low. Also, if atmospheric methane and carbon dioxide were as abundant now as they were in Earth’s earliest atmosphere, the planet’s temperature would likely be too hot for most species living today. How and when did the atmosphere change?
The answer to this riddle lies in the metabolic activity of early photosynthetic life-forms that slowly but surely transformed the chemical composition of Earth’s atmosphere. Some of these early organisms were photosynthetic relatives of modern cyanobacteria (blue-green bacteria). In the process of photosynthesis, carbon dioxide gas combined with water yields oxygen. In Earth’s early days, all over the planet countless photosynthetic bacteria performed photosynthesis. Together, these ancient bacteria removed massive amounts of carbon dioxide from Earth’s atmosphere by converting it to solid organic carbon. These ancient bacteria also released huge quantities of oxygen into the atmosphere. Other ancient bacteria consumed methane, greatly reducing its amount in the atmosphere. When our Sun later became hotter, the continued removal of atmospheric carbon dioxide and methane by early bacteria kept Earth’s climate from becoming too hot to sustain life. Modern cyanobacteria still provide these valuable services today.
The bacterial oxygen release improved conditions for life in two ways. First, oxygen is essential for the metabolic process known as cell respiration that allows cells to efficiently harvest energy from organic food. Second, oxygen in the upper atmosphere reacts to form a protective shield of ozone. Earth is constantly bombarded by harmful ultraviolet (UV) radiation from the Sun. Today, Earth’s upper-atmosphere ozone shield absorbs enough UV to allow diverse forms of life to survive. But because early Earth lacked oxygen in its atmosphere, it also lacked a protective ozone barrier. As a result, early life on Earth was confined to the oceans, where the water absorbed the UV radiation. Only after oxygen released by ancient bacteria drifted up into the upper atmosphere and reacted with other oxygen molecules to form a protective layer of ozone could life flourish at the surface and on the land. The absence of an oxygen atmosphere on Mars and other planets in our solar system means that these planets also lack an ozone shield that would protect surface-dwelling life from UV radiation. The surface of Mars is bombarded with deadly radiation; if any life exists on Mars, it would almost certainly be subterranean.
Early life-forms and Earth’s Atmosphere
原始生命与地球大气
重复2014.06.15
先讲了生物形成的条件，第一是离太阳的位置刚刚好；第二是先有bacteria，然后才有更加复杂的生物；原始的大气层是由一些methane和二氧化碳组成，温室气体，在当时太阳不是那么bright的时候（dim period）提供了一些热量，可以使早期生物生存；现在的地球是氢气和氧气主要组成，如果现在的大气层还和之前一样那么多methane和二氧化碳的话，地球会too hot for organisms to survive（这里考到一个题，早期和现在的大气区别）；然后又说到细菌产生的氧气可以阻挡UV（紫外线），为生物提供protection，而其他planet没有氧气，所以生物无法生存。
altered = transformed 改变
emitted = released 释放
retarding = slowing 迟滞，延迟
abundant = plentiful 大量的
sustain = support 支持
真题原文
Early life-forms and Earth’s Atmosphere
Why has life flourished on Earth? This question has a two-part answer. First, Earth has been a cradle for life because of its position relative to the Sun. second, once life began on Earth, simple early life-forms (photosynthetic bacteria) slowly but inexorably altered the environment in a manner that not only maintained life but also paved the way for later, complex life-forms. These changes allowed later organisms to evolve and thrive. Humans and other higher organisms owe their life-supporting environment to these early life-forms.
Earth’s earliest atmosphere contained several gases: hydrogen, water vapor, ammonia, nitrogen, methane, and carbon dioxide, but no oxygen. Gas mixtures emitted from present-day volcanoes resemble this early atmosphere, suggesting its origin from volcanic eruptions. In Earth’s earliest atmosphere, methane and carbon dioxide occurred at much higher levels than at present—a circumstance that was favorable for early life. Methane and carbon dioxide are greenhouse gases that warm atmospheres by retarding loss of heat to space. These two gases kept Earth warm during the Sun’s early history, when the Sun did not burn as brightly as it now does. (An early dim period, with later brightening, is normal for stars of our Sun’s type.)
Earth’s modern atmosphere, which is 78 percent nitrogen gas, 21 percent oxygen, and about 1 percent argon, water vapor, ozone, and carbon dioxide, differs dramatically from the earliest atmosphere just described. The modern atmosphere supports many forms of complex life that would not have been able to exist in Earth’s first atmosphere because the oxygen level was too low. Also, if atmospheric methane and carbon dioxide were as abundant now as they were in Earth’s earliest atmosphere, the planet’s temperature would likely be too hot for most species living today. How and when did the atmosphere change?
The answer to this riddle lies in the metabolic activity of early photosynthetic life-forms that slowly but surely transformed the chemical composition of Earth’s atmosphere. Some of these early organisms were photosynthetic relatives of modern cyanobacteria (blue-green bacteria). In the process of photosynthesis, carbon dioxide gas combined with water yields oxygen. In Earth’s early days, all over the planet countless photosynthetic bacteria performed photosynthesis. Together, these ancient bacteria removed massive amounts of carbon dioxide from Earth’s atmosphere by converting it to solid organic carbon. These ancient bacteria also released huge quantities of oxygen into the atmosphere. Other ancient bacteria consumed methane, greatly reducing its amount in the atmosphere. When our Sun later became hotter, the continued removal of atmospheric carbon dioxide and methane by early bacteria kept Earth’s climate from becoming too hot to sustain life. Modern cyanobacteria still provide these valuable services today.
The bacterial oxygen release improved conditions for life in two ways. First, oxygen is essential for the metabolic process known as cell respiration that allows cells to efficiently harvest energy from organic food. Second, oxygen in the upper atmosphere reacts to form a protective shield of ozone. Earth is constantly bombarded by harmful ultraviolet (UV) radiation from the Sun. Today, Earth’s upper-atmosphere ozone shield absorbs enough UV to allow diverse forms of life to survive. But because early Earth lacked oxygen in its atmosphere, it also lacked a protective ozone barrier. As a result, early life on Earth was confined to the oceans, where the water absorbed the UV radiation. Only after oxygen released by ancient bacteria drifted up into the upper atmosphere and reacted with other oxygen molecules to form a protective layer of ozone could life flourish at the surface and on the land. The absence of an oxygen atmosphere on Mars and other planets in our solar system means that these planets also lack an ozone shield that would protect surface-dwelling life from UV radiation. The surface of Mars is bombarded with deadly radiation; if any life exists on Mars, it would almost certainly be subterranean.
02
Birdsong
鸟鸣
重复2015.01.11，2016.03.26
刚出生时不会叫，学习父母来发声，某wild鸟类野外比实验室叫的早（宣告自己的存在）。鸟类有一个对它们来说非常关键的学习期，期间可以学习一切声音，并且过后还能一直记得，鸟类成熟后受环境的影响，只会学习同种鸟类的发声。
Pic：chaffinch birds
pioneering = original 最初的
distinct = separate 不同的，各自的
enabling = allowing 允许，使能够
restricted = limited 受限的
真题原文
Birdsong
Birdsong is the classic example of how genes (hereditary information) and environment both have a crucial role to play in the behavioral development of animals. Since the pioneering work of W. H. Thorpe on chaffinches (a common European bird), many species have been studied, and it has become clear both that learning plays an important role for all species and also that there are constraints on what they are able to learn.
Thorpe was able to show that learning from others was involved in chaffinch birds through a series of experiments on hand-reared chicks (young birds). As in most other species, only the males sing. Thorpe found that, if he raised young males in total isolation from all others, the song they produced was quite different from that of a normal adult. It was about the right length and in the correct frequency range. It was also split up into a series of notes as it should be. But these notes lacked the detailed structure found in wild birds, nor was the song split up into distinct phrases as it usually is. This suggested that song development requires some social influence. Later experiments in which researchers played recordings of songs to young birds showed just how precise this influence was: many of them would learn the exact pattern of the recording they had heard. A remarkable feature here was that birds were able to copy precisely songs that they only heard in the first few weeks of life, yet they did not sing themselves until about eight months old. They are thus able to store a memory of the sound within their brain and then match their own output to their recollection of it when they mature.
Young chaffinches normally learn only chaffinch song, though Thorpe found they could be trained to sing the song of a tree pipit (another type of bird), which is very similar to that of their own species. In general, however, the constraints on learning which birds have ensure that they only learn songs appropriate to the species to which they themselves belong. These constraints may be in their brain’s circuitry, the young bird hatching with a rough idea of the sounds that it should copy. The crude song of a bird reared in isolation gives some clues as to what this rough idea may be: the length, the frequency range and the breaking up into notes are all aspects of chaffinch song shared between normal birds and those reared in isolation. In other cases the constraints are more social, young birds only being prepared to learn from individuals with whom they have social interactions. Thus, in a number of species, it has been found that they will not copy from recordings, but will do so from a live tutor. In some cases this may occur when they are young birds, but in others the main learning period is when they set up their territories and interact with neighbors for the first time, enabling them to match their neighbor’s songs and so countersing with them. Whatever the nature of the learning rules in a particular species, there is no doubt that they are effective; it is very unusual to hear a wild bird singing a song which is not typical of its own species despite the many different songs which often occur in a small patch of woodland.
However, not all birds show the same learning pattern as do chaffinches. There are some species which produce normal sounds even if deaf, so that they cannot hear their own efforts, much less copy those of others. The cooing of doves and the crowing of cocks are examples here. In other cases, such as parrots and hill mynahs, birds can be trained to copy a huge variety of sounds, though those they learn in the wild are usually more restricted. The amazing capability of mynahs has apparently arisen simply because birds in an area learn a small number of their calls from each other, males from males and females from females, and these calls are highly varied in structure. The ability to master them has led the birds, incidentally, to be capable of saying “hello” and mimicking a wide variety of other sounds.
03
沙漠地区的农业
Agriculture in desert area(how to solve the problem)解决水资源短缺的问题。
话题重复
【水资源获取】【农业生产中对水资源的利用与开发】话题可参考：
TPO 3 Depletion of Ogallala Aquifer
TPO 14 Maya Water Problem
TPO 29 History of Waterpower
【沙漠环境中的水】话题可参考：
TPO 12 Water in the Desert
真题原文可参考：
Water Management in Early Agriculture
As the first cities formed in Mesopotamia in the Middle East, probably around 3000 B.C., it became necessarily to provide food for larger populations, and thus to find ways of increasing agricultural production. This, in turn, led to the problem of obtaining sufficient water.
Irrigation must have started on a small scale with rather simple constructions, but as its value became apparent, more effort was invested in new construction to divert more water into the canals and to extend the canal system to reach greater areas of potential farmland. Because of changing water levels and clogging by waterborne particles, canals and their intakes required additional labor to maintain, besides the normal labor required to guide water from field to field. Beyond this,some personnel had to be devoted to making decisions about the allocation of available water among the users and ensuring that these directions were carried out. With irrigation water also came potential problems, the most obvious being the susceptibility of low-lying farmlands to disastrous flooding and the longer-term problem of salinization (elevated levels of salt in the soil). To combat flooding from rivers, people from early historic times until today have constructed protective levees (raised barriers of earth) between the river and the settlement or fields to be protected. This, of course, is effective up to a certain level of flooding but changes the basic water patterns of the area and can multiply the damage when the flood level exceeds the height of the levee.
Salinization is caused by an accumulation of salt in the soil near its surface. This salt is carried by river water from the sedimentary rocks in the mountains and deposited on the Mesopotamian fields during natural flooding or purposeful irrigation. Evaporation of water sitting on the surface in hot climates is rapid, concentrating the salts in the remaining water that then descends through the soil to the underlying water table. In southern Mesopotamia, for example, the natural water table comes to within roughly six feet of the surface. Conditions of excessive irrigation bring the water table to eighteen inches, and water can rise further to the root zone, where the high concentration of salts would kill most plants.
Birdsong
鸟鸣
重复2015.01.11，2016.03.26
刚出生时不会叫，学习父母来发声，某wild鸟类野外比实验室叫的早（宣告自己的存在）。鸟类有一个对它们来说非常关键的学习期，期间可以学习一切声音，并且过后还能一直记得，鸟类成熟后受环境的影响，只会学习同种鸟类的发声。
Pic：chaffinch birds
pioneering = original 最初的
distinct = separate 不同的，各自的
enabling = allowing 允许，使能够
restricted = limited 受限的
真题原文
Birdsong
Birdsong is the classic example of how genes (hereditary information) and environment both have a crucial role to play in the behavioral development of animals. Since the pioneering work of W. H. Thorpe on chaffinches (a common European bird), many species have been studied, and it has become clear both that learning plays an important role for all species and also that there are constraints on what they are able to learn.
Thorpe was able to show that learning from others was involved in chaffinch birds through a series of experiments on hand-reared chicks (young birds). As in most other species, only the males sing. Thorpe found that, if he raised young males in total isolation from all others, the song they produced was quite different from that of a normal adult. It was about the right length and in the correct frequency range. It was also split up into a series of notes as it should be. But these notes lacked the detailed structure found in wild birds, nor was the song split up into distinct phrases as it usually is. This suggested that song development requires some social influence. Later experiments in which researchers played recordings of songs to young birds showed just how precise this influence was: many of them would learn the exact pattern of the recording they had heard. A remarkable feature here was that birds were able to copy precisely songs that they only heard in the first few weeks of life, yet they did not sing themselves until about eight months old. They are thus able to store a memory of the sound within their brain and then match their own output to their recollection of it when they mature.
Young chaffinches normally learn only chaffinch song, though Thorpe found they could be trained to sing the song of a tree pipit (another type of bird), which is very similar to that of their own species. In general, however, the constraints on learning which birds have ensure that they only learn songs appropriate to the species to which they themselves belong. These constraints may be in their brain’s circuitry, the young bird hatching with a rough idea of the sounds that it should copy. The crude song of a bird reared in isolation gives some clues as to what this rough idea may be: the length, the frequency range and the breaking up into notes are all aspects of chaffinch song shared between normal birds and those reared in isolation. In other cases the constraints are more social, young birds only being prepared to learn from individuals with whom they have social interactions. Thus, in a number of species, it has been found that they will not copy from recordings, but will do so from a live tutor. In some cases this may occur when they are young birds, but in others the main learning period is when they set up their territories and interact with neighbors for the first time, enabling them to match their neighbor’s songs and so countersing with them. Whatever the nature of the learning rules in a particular species, there is no doubt that they are effective; it is very unusual to hear a wild bird singing a song which is not typical of its own species despite the many different songs which often occur in a small patch of woodland.
However, not all birds show the same learning pattern as do chaffinches. There are some species which produce normal sounds even if deaf, so that they cannot hear their own efforts, much less copy those of others. The cooing of doves and the crowing of cocks are examples here. In other cases, such as parrots and hill mynahs, birds can be trained to copy a huge variety of sounds, though those they learn in the wild are usually more restricted. The amazing capability of mynahs has apparently arisen simply because birds in an area learn a small number of their calls from each other, males from males and females from females, and these calls are highly varied in structure. The ability to master them has led the birds, incidentally, to be capable of saying “hello” and mimicking a wide variety of other sounds.
03
沙漠地区的农业
Agriculture in desert area(how to solve the problem)解决水资源短缺的问题。
话题重复
【水资源获取】【农业生产中对水资源的利用与开发】话题可参考：
TPO 3 Depletion of Ogallala Aquifer
TPO 14 Maya Water Problem
TPO 29 History of Waterpower
【沙漠环境中的水】话题可参考：
TPO 12 Water in the Desert
真题原文可参考：
Water Management in Early Agriculture
As the first cities formed in Mesopotamia in the Middle East, probably around 3000 B.C., it became necessarily to provide food for larger populations, and thus to find ways of increasing agricultural production. This, in turn, led to the problem of obtaining sufficient water.
Irrigation must have started on a small scale with rather simple constructions, but as its value became apparent, more effort was invested in new construction to divert more water into the canals and to extend the canal system to reach greater areas of potential farmland. Because of changing water levels and clogging by waterborne particles, canals and their intakes required additional labor to maintain, besides the normal labor required to guide water from field to field. Beyond this,some personnel had to be devoted to making decisions about the allocation of available water among the users and ensuring that these directions were carried out. With irrigation water also came potential problems, the most obvious being the susceptibility of low-lying farmlands to disastrous flooding and the longer-term problem of salinization (elevated levels of salt in the soil). To combat flooding from rivers, people from early historic times until today have constructed protective levees (raised barriers of earth) between the river and the settlement or fields to be protected. This, of course, is effective up to a certain level of flooding but changes the basic water patterns of the area and can multiply the damage when the flood level exceeds the height of the levee.
Salinization is caused by an accumulation of salt in the soil near its surface. This salt is carried by river water from the sedimentary rocks in the mountains and deposited on the Mesopotamian fields during natural flooding or purposeful irrigation. Evaporation of water sitting on the surface in hot climates is rapid, concentrating the salts in the remaining water that then descends through the soil to the underlying water table. In southern Mesopotamia, for example, the natural water table comes to within roughly six feet of the surface. Conditions of excessive irrigation bring the water table to eighteen inches, and water can rise further to the root zone, where the high concentration of salts would kill most plants.
Solutions for salinization were not as straightforward as for flooding, but even in ancient times it was understood that the deleterious effects of salinization could be minimized by removing harmful elements through leaching the fields with additional fresh water, digging deep wells to lower the water table, or instituting a system of leaving fields uncultivated. The first two cures would have required considerable labor, and the third solution would have led to diminished productivity, not often viewed as a likely decision in periods of growing population. An effective irrigation system laid the foundation for many of the world’s early civilizations, but it also required a great deal of labor input.
Growing agrarian societies often tried to meet their food-producing needs by farming less-desirable hill slopes surrounding the favored low-lying valley bottoms. Since bringing irrigation water to a hill slope is usually impractical, the key is effective utilization of rainfall. Rainfall either soaks into the soil or runs off of it due to gravity. A soil that is deep, well-structured, and covered by protective vegetation and much will normally absorb almost all of the rain that falls on it, provided that the slope is not too steep. However, soils that have lost their vegetative cover and surface mulch will absorb much less, with almost half the water being carried away by runoff in more extreme conditions. This runoff carries with it topsoil particles, nutrients, and humus (decayed vegetable matter) that are concentrated in the topsoil. The loss of this material reduces the thickness of the rooting zone and its capacity to absorb moisture for crop needs.
The most direct solution to this problem of slope runoff was to lay lines of stones along the contours of the slope and hence, perpendicular to the probable flow of water and sediment. These stones could then act as small dams, slowing the downhill flow of water and allowing more water to infiltrate and soil particles to collect behind the dam. This provided a buildup of sediments for plants and improved the landscape’s water-retention properties.
04
沙漠环境中的动植物
话题参考：
TPO 26 Survival of Plants and Animals in Desert Conditions
05
Gliding and Soaring
滑翔与高飞
重复2015.09.12
真题原文
Gliding is gravity-powered flight where the movement of the glider has a downward tilt. But many birds are capable of ascending without flapping their wings, and this is called soaring.Birds usually soar by finding air that is rising as fast as or faster than the gliding bird's sinking speed. For example, a turkey vulture might glide with a sinking speed of about 0.8 meters per second. If the vulture can find a place where the air is rising at 0.8 meters per second, it will be able to maintain a constant altitude. If it finds air rising faster than that, it will be able to climb.
Two common processes produce updrafts, or rising air. When heated air rises, it is called a thermal, and when wind blows up a hill or over a large obstacle, it is called ridge lift or slope lift. Thermals occur when the Sun heats some parts of the ground more than others. For example, a freshly plowed field may heat up faster than an adjacent meadow. The warm ground heats the air above it, and the air starts to rise. As the warm air rises, it is replaced by cool air from the surrounding terrain, and this new air is heated until it rises. Thermals may be continuous chimneys of rising air, or a series of discrete, doughnut-shaped bubbles (ring thermals) formed at intervals by the warmed ground.
If they could be made visible, ring thermals would look like giant, rising smoke rings. Some airplane pilots and biologists disagree about the exact form of continuous thermal chimneys. Pilots have traditionally interpreted thermals as large, tall columns of rising air, usually with a cumulus (white, fluffy) cloud marking the top of the column. In contrast, observers of animal flight find only small, localized thermal chimneys, which usually take the form of dust devils, which are small columnar thermals with intense rotation. Colin Pennycuick, a prolific researcher on bird flight, discounts thermal chimneys and recognizes only ring thermals as sources of large-scale, long-lasting updrafts. In any case, thermals can rise 2 or 3 kilometers above the ground. Also, they tend to increase in size and intensity as they rise, sometimes reaching over 1,000 meters in diameter. Thermals are usually capped by a cloud, because the upper limit of a thermal is set by the altitude where the temperature is low enough to condense water vapor in the thermal, which cools the air and forms a cloud.
As long as the upward speed of the thermal is greater than the sinking speed of a glider, the glider will ascend in the thermal. Of course, the glider will quickly fly out of the thermal if it flies in a straight line, so it must circle to stay in the rising air. (A glider should stay on the inside of the ring, because the air on the outer edge of the ring is actually rolling downward.) Imagine a vulture ascending to 1,500 meters above the ground by circling in a ring thermal. From this height, it will be able to fly out of the thermal and glide for about 30 minutes (traveling over 23 kilometers) before it runs out of altitude and needs to either start flapping, find another thermal, or land. Many soaring birds use just this pattern: climbing up in a thermal, gliding a long distance, then finding another thermal in which to soar. This type of flight is an efficient way to cover long distances at a low energy cost, making it a handy way to migrate or search for food.
Growing agrarian societies often tried to meet their food-producing needs by farming less-desirable hill slopes surrounding the favored low-lying valley bottoms. Since bringing irrigation water to a hill slope is usually impractical, the key is effective utilization of rainfall. Rainfall either soaks into the soil or runs off of it due to gravity. A soil that is deep, well-structured, and covered by protective vegetation and much will normally absorb almost all of the rain that falls on it, provided that the slope is not too steep. However, soils that have lost their vegetative cover and surface mulch will absorb much less, with almost half the water being carried away by runoff in more extreme conditions. This runoff carries with it topsoil particles, nutrients, and humus (decayed vegetable matter) that are concentrated in the topsoil. The loss of this material reduces the thickness of the rooting zone and its capacity to absorb moisture for crop needs.
The most direct solution to this problem of slope runoff was to lay lines of stones along the contours of the slope and hence, perpendicular to the probable flow of water and sediment. These stones could then act as small dams, slowing the downhill flow of water and allowing more water to infiltrate and soil particles to collect behind the dam. This provided a buildup of sediments for plants and improved the landscape’s water-retention properties.
04
沙漠环境中的动植物
话题参考：
TPO 26 Survival of Plants and Animals in Desert Conditions
05
Gliding and Soaring
滑翔与高飞
重复2015.09.12
真题原文
Gliding is gravity-powered flight where the movement of the glider has a downward tilt. But many birds are capable of ascending without flapping their wings, and this is called soaring.Birds usually soar by finding air that is rising as fast as or faster than the gliding bird's sinking speed. For example, a turkey vulture might glide with a sinking speed of about 0.8 meters per second. If the vulture can find a place where the air is rising at 0.8 meters per second, it will be able to maintain a constant altitude. If it finds air rising faster than that, it will be able to climb.
Two common processes produce updrafts, or rising air. When heated air rises, it is called a thermal, and when wind blows up a hill or over a large obstacle, it is called ridge lift or slope lift. Thermals occur when the Sun heats some parts of the ground more than others. For example, a freshly plowed field may heat up faster than an adjacent meadow. The warm ground heats the air above it, and the air starts to rise. As the warm air rises, it is replaced by cool air from the surrounding terrain, and this new air is heated until it rises. Thermals may be continuous chimneys of rising air, or a series of discrete, doughnut-shaped bubbles (ring thermals) formed at intervals by the warmed ground.
If they could be made visible, ring thermals would look like giant, rising smoke rings. Some airplane pilots and biologists disagree about the exact form of continuous thermal chimneys. Pilots have traditionally interpreted thermals as large, tall columns of rising air, usually with a cumulus (white, fluffy) cloud marking the top of the column. In contrast, observers of animal flight find only small, localized thermal chimneys, which usually take the form of dust devils, which are small columnar thermals with intense rotation. Colin Pennycuick, a prolific researcher on bird flight, discounts thermal chimneys and recognizes only ring thermals as sources of large-scale, long-lasting updrafts. In any case, thermals can rise 2 or 3 kilometers above the ground. Also, they tend to increase in size and intensity as they rise, sometimes reaching over 1,000 meters in diameter. Thermals are usually capped by a cloud, because the upper limit of a thermal is set by the altitude where the temperature is low enough to condense water vapor in the thermal, which cools the air and forms a cloud.
As long as the upward speed of the thermal is greater than the sinking speed of a glider, the glider will ascend in the thermal. Of course, the glider will quickly fly out of the thermal if it flies in a straight line, so it must circle to stay in the rising air. (A glider should stay on the inside of the ring, because the air on the outer edge of the ring is actually rolling downward.) Imagine a vulture ascending to 1,500 meters above the ground by circling in a ring thermal. From this height, it will be able to fly out of the thermal and glide for about 30 minutes (traveling over 23 kilometers) before it runs out of altitude and needs to either start flapping, find another thermal, or land. Many soaring birds use just this pattern: climbing up in a thermal, gliding a long distance, then finding another thermal in which to soar. This type of flight is an efficient way to cover long distances at a low energy cost, making it a handy way to migrate or search for food.
Solutions for salinization were not as straightforward as for flooding, but even in ancient times it was understood that the deleterious effects of salinization could be minimized by removing harmful elements through leaching the fields with additional fresh water, digging deep wells to lower the water table, or instituting a system of leaving fields uncultivated. The first two cures would have required considerable labor, and the third solution would have led to diminished productivity, not often viewed as a likely decision in periods of growing population. An effective irrigation system laid the foundation for many of the world’s early civilizations, but it also required a great deal of labor input.
Growing agrarian societies often tried to meet their food-producing needs by farming less-desirable hill slopes surrounding the favored low-lying valley bottoms. Since bringing irrigation water to a hill slope is usually impractical, the key is effective utilization of rainfall. Rainfall either soaks into the soil or runs off of it due to gravity. A soil that is deep, well-structured, and covered by protective vegetation and much will normally absorb almost all of the rain that falls on it, provided that the slope is not too steep. However, soils that have lost their vegetative cover and surface mulch will absorb much less, with almost half the water being carried away by runoff in more extreme conditions. This runoff carries with it topsoil particles, nutrients, and humus (decayed vegetable matter) that are concentrated in the topsoil. The loss of this material reduces the thickness of the rooting zone and its capacity to absorb moisture for crop needs.
The most direct solution to this problem of slope runoff was to lay lines of stones along the contours of the slope and hence, perpendicular to the probable flow of water and sediment. These stones could then act as small dams, slowing the downhill flow of water and allowing more water to infiltrate and soil particles to collect behind the dam. This provided a buildup of sediments for plants and improved the landscape’s water-retention properties.
04
沙漠环境中的动植物
话题参考：
TPO 26 Survival of Plants and Animals in Desert Conditions
05
Gliding and Soaring
滑翔与高飞
重复2015.09.12
真题原文
Gliding is gravity-powered flight where the movement of the glider has a downward tilt. But many birds are capable of ascending without flapping their wings, and this is called soaring.Birds usually soar by finding air that is rising as fast as or faster than the gliding bird's sinking speed. For example, a turkey vulture might glide with a sinking speed of about 0.8 meters per second. If the vulture can find a place where the air is rising at 0.8 meters per second, it will be able to maintain a constant altitude. If it finds air rising faster than that, it will be able to climb.
Two common processes produce updrafts, or rising air. When heated air rises, it is called a thermal, and when wind blows up a hill or over a large obstacle, it is called ridge lift or slope lift. Thermals occur when the Sun heats some parts of the ground more than others. For example, a freshly plowed field may heat up faster than an adjacent meadow. The warm ground heats the air above it, and the air starts to rise. As the warm air rises, it is replaced by cool air from the surrounding terrain, and this new air is heated until it rises. Thermals may be continuous chimneys of rising air, or a series of discrete, doughnut-shaped bubbles (ring thermals) formed at intervals by the warmed ground.
If they could be made visible, ring thermals would look like giant, rising smoke rings. Some airplane pilots and biologists disagree about the exact form of continuous thermal chimneys. Pilots have traditionally interpreted thermals as large, tall columns of rising air, usually with a cumulus (white, fluffy) cloud marking the top of the column. In contrast, observers of animal flight find only small, localized thermal chimneys, which usually take the form of dust devils, which are small columnar thermals with intense rotation. Colin Pennycuick, a prolific researcher on bird flight, discounts thermal chimneys and recognizes only ring thermals as sources of large-scale, long-lasting updrafts. In any case, thermals can rise 2 or 3 kilometers above the ground. Also, they tend to increase in size and intensity as they rise, sometimes reaching over 1,000 meters in diameter. Thermals are usually capped by a cloud, because the upper limit of a thermal is set by the altitude where the temperature is low enough to condense water vapor in the thermal, which cools the air and forms a cloud.
As long as the upward speed of the thermal is greater than the sinking speed of a glider, the glider will ascend in the thermal. Of course, the glider will quickly fly out of the thermal if it flies in a straight line, so it must circle to stay in the rising air. (A glider should stay on the inside of the ring, because the air on the outer edge of the ring is actually rolling downward.) Imagine a vulture ascending to 1,500 meters above the ground by circling in a ring thermal. From this height, it will be able to fly out of the thermal and glide for about 30 minutes (traveling over 23 kilometers) before it runs out of altitude and needs to either start flapping, find another thermal, or land. Many soaring birds use just this pattern: climbing up in a thermal, gliding a long distance, then finding another thermal in which to soar. This type of flight is an efficient way to cover long distances at a low energy cost, making it a handy way to migrate or search for food.
Slope soaring is useful when wind blows upward along a slope. The speed of the wind's upward motion can be calculated in the same manner that the sinking speed of a glider is calculated. If the upward speed of this wind is greater than or equal to the sinking speed of a glider, the glider will be able to maintain altitude. Such ridge lift has a characteristic that is both an advantage and a disadvantage: ridge lift is usually predictably tied to a particular slope, so it is easy to find. But it is usable only in that fixed, local area.
at intervals = periodically时不时地
discrete = separate不连续的
prolific = highly productive多产的
adjacent = nearby邻近的
英联全球雅思托福英语Q1 15:01:45
06
The Impact of Industrialization on Labor Systems
工业革命对劳动力系统的影响
重复2016.03.11，2017.07.15上午场，2017.11.11，2018.03.10
工业革命给劳动力带来了很多影响如工具替换了人力，工具的好处是很高效强力并且很精确，能够长时间工作。一些孩子们，虽然在工业早期有时候能够挨近着亲人去工作，也发现他们的工作-家庭关系被重新定义，被工业化的工作从家庭环境中迁出去而重新定义了，在这里的最终解决办法是去把孩子完全拉出劳动力。另一结果是每个人都不是fully skilled，只对某一块熟练所以工厂开除员工很容易成本低，导致人们即使在这么多冲击下也愿意工作。家庭和工作之间隔开的距离，（工人们已经暴露于比他们先前所习惯的更大的场地工作），意味着工人们不得不去应对陌生人了。这样的一系列操作使得进一步促进了工业革命。
components = pieces 组成部分
peak = maximum 最高
gradual = slow 缓慢的
adapt = adjust 适应
07
Pest Control
虫害控制
重复2014.05.25，2017.04.01
对外来引入的非本土害虫，由于没有天敌存在，所以无法根除，对它们人类要采取有效的好虫控制方法。分别从化学法、生物法、综合法三个方面来介绍。
真题原文
Pest Control
Many pest species that are native to North America, such as white-footed mice and ground moles, are more nuisance pests and are usually regulated by native predators and parasites. This situation is not true for nonindigenous pests in North America, such as brown rats and cockroaches. After centuries, it is evident that these pests cannot be eradicated. The best that can be done is to introduce pest control measures that will control their numbers.
And ancient and popular means of pest control is chemical. For example, the Sumerians used sulfur to combat crop pests, and by the early 1800s such chemicals as arsenic were used to combat insect and fungal pests.
However, chemical control has its dark side. Chemical pesticides have many unintended consequences through their effects not just on the target species but on a wide array of nontarget species as well, often eliminating them and thereby upsetting the existing food webs, especially through the suppression of native predator species. The surviving pests then rebound in greater numbers than ever.
Perhaps more insidious is that a pesticide loses its effectiveness because the target species evolves resistance to it. As one pesticide replaces another, the pests acquire a resistance to them all. Some species, notably certain mosquitoes, have overcome the toxic effects of every pesticide to which they have been exposed. Insect pests need not only about five years to evolve pesticide resistance, their predators do so much more slowly. So after the pest develops resistance, pest outbreaks become even more disastrous.
Farmer long ago observed that enemies of pests act as controls. As early as 300 C.E., the Chinese were introducing predatory ants into their citrus orchards to control leaf-eating caterpillars. Insect pests have their own array of enemies in their native habitats. When an animal or plant is introduced, intentionally or unintentionally, into a new habitat outside of its natural range, it may adapt to the new environment and leave its enemies behind. Freed from predation and finding and abundance of resources, the species quickly becomes a pest or a weed. This fact had led to the search for natural enemies to introduce into populations of pests to reduce their populations.
Because the serious pest is usually a nonnative species, biological control involves the introduction of a nonindigenous predator or parasite to control the pest. The introduction of the cactus-eating moth, a native of Argentina, into Australia effectively reduced and controlled the rapidly spreading prickly pear, which had been introduced into Australia in 1901.
But biological control, like chemical control, can backfire. The success of the cactus-feeding moth in controlling prickly pear in Australia encouraged its introduction to several West Indies islands to control prickly pear there. In time the moth made its way to Florida, where it now threatens the existence of several native prickly pear species. The moral is that although using nonindigenous predators as biological controls can be effective, these species possess their own inherent dangers that must be assessed before they are released. They, too, can become alien invaders.
Because chemical, biological, and other methods used individually are obviously not the solution to pest control, entomologists have developed a holistic approach to pest control, called integrated pest management (IPM). IPM considers the biological, ecological, economic, social, and even aesthetic aspects of pest control and employs a variety of techniques. The objective of IPM is to control the pest not at the time a major outbreak but at an earlier time, when the size of the population is easier to control. The approach is to rely first on natural mortality caused by weather and natural enemies, with as little disruption of the natural system as possible, and to use other methods only if they are needed to hold the pest below the economic injury level.
Successful IPM requires the knowledge of the population ecology of each pest and its associated species and the dynamics of the host species. It involves considerable field work monitoring the pest species and its natural enemies by such techniques as egg counts and the trapping of adults to acquire information to determine the necessity, timing, and intensity of control measures. These control measures must be adjusted to the situation, which may vary from one location to another. The intensity of control or no control is based on the degree of pest damage that can be tolerated, the costs of control, and the benefits to be derived.
08
Evidence of Zooxanthellae in Fossilized Corals
虫黄藻在石化的珊瑚里的证据
重复→2018.03.10
本文介绍了虫黄藻在石化的珊瑚里的证据且提到了珊瑚和Z的一种寄生关系。珊瑚提供保护，z提供光合作用产生的二氧化碳，但寄生珊瑚不能在太低温度或太深的海底因为光照不到——z光合作用也就不行了。但有些也不是寄生的，判断寄生方法是同位素，z需要C12而非C13。多余C13排放被珊瑚吸收，所以C13多的珊瑚就存在寄生关系。此外在判断化石生长速度时可以用X ray来测定出类似于树木年轮一样的记录，有些珊瑚不存在寄生关系仍然可以生存是因为海水深度的变化并不会影响珊瑚的生长速度。
09
南亚昆虫的翅膀
10
人口发展与食物供给之间的关系
第一段：中国的人口有很大的增长，因为sweet potato和另外两种食物的出现，它们可以在非常干旱的条件下生长，rice却不行，而且可以一年种植两三次；
第二段：欧洲人口也有增长；
第三段：技术方面的发展促进这种增长，介绍了两个技术；
第四段：但是食物的增长却没办法keep in pace with人口的增长。
11
婴儿的早期行为
whether instinct or learned（两个对立流派的观点，对比结构证明类文章）
12
Dinosaurs and Parental Care
恐龙的亲本养育
重复2018.07.01,2015.02.01，2014.08.23
alleged = supposed 所谓的
controversial = debatable 有争议的
inconclusive = not decisive 无定论的
13
Logging
树木砍伐对生态的影响
以前美洲欧洲等大陆存在着许多的森林，但是现在只有温带才有大量的森林，而热带的森林正在越来越少。原因之一就是人类的伐木行为。人们的伐木行为通常都有一定的偏好，专门爱砍伐某种特定的树木，这种行为会影响植物的多样性，进而影响依赖这种树木生存的动物，所以还会影响动物的多样性。接着文章讲述了伐木对整体环境的影响，伐木带来了水土流失（faster runoff），水土流失导致土壤的颗粒进入到河流小溪里，这样就影响了鱼类的产卵，直接导致了鱼的数量的减少。另外讲了木来来说最经济划算的一种伐木方式，但是这种方式也存在以上的种种弊端，有一个解决办法就是在临河的斜坡上保留一片不被砍伐的树木带，这些树木既可以保护河堤，而且树木的阴影可以使得河面的温度相对较低，这样又保护了鱼的生存环境。
14 19世纪的印象派艺术
Growing agrarian societies often tried to meet their food-producing needs by farming less-desirable hill slopes surrounding the favored low-lying valley bottoms. Since bringing irrigation water to a hill slope is usually impractical, the key is effective utilization of rainfall. Rainfall either soaks into the soil or runs off of it due to gravity. A soil that is deep, well-structured, and covered by protective vegetation and much will normally absorb almost all of the rain that falls on it, provided that the slope is not too steep. However, soils that have lost their vegetative cover and surface mulch will absorb much less, with almost half the water being carried away by runoff in more extreme conditions. This runoff carries with it topsoil particles, nutrients, and humus (decayed vegetable matter) that are concentrated in the topsoil. The loss of this material reduces the thickness of the rooting zone and its capacity to absorb moisture for crop needs.
The most direct solution to this problem of slope runoff was to lay lines of stones along the contours of the slope and hence, perpendicular to the probable flow of water and sediment. These stones could then act as small dams, slowing the downhill flow of water and allowing more water to infiltrate and soil particles to collect behind the dam. This provided a buildup of sediments for plants and improved the landscape’s water-retention properties.
04
沙漠环境中的动植物
话题参考：
TPO 26 Survival of Plants and Animals in Desert Conditions
05
Gliding and Soaring
滑翔与高飞
重复2015.09.12
真题原文
Gliding is gravity-powered flight where the movement of the glider has a downward tilt. But many birds are capable of ascending without flapping their wings, and this is called soaring.Birds usually soar by finding air that is rising as fast as or faster than the gliding bird's sinking speed. For example, a turkey vulture might glide with a sinking speed of about 0.8 meters per second. If the vulture can find a place where the air is rising at 0.8 meters per second, it will be able to maintain a constant altitude. If it finds air rising faster than that, it will be able to climb.
Two common processes produce updrafts, or rising air. When heated air rises, it is called a thermal, and when wind blows up a hill or over a large obstacle, it is called ridge lift or slope lift. Thermals occur when the Sun heats some parts of the ground more than others. For example, a freshly plowed field may heat up faster than an adjacent meadow. The warm ground heats the air above it, and the air starts to rise. As the warm air rises, it is replaced by cool air from the surrounding terrain, and this new air is heated until it rises. Thermals may be continuous chimneys of rising air, or a series of discrete, doughnut-shaped bubbles (ring thermals) formed at intervals by the warmed ground.
If they could be made visible, ring thermals would look like giant, rising smoke rings. Some airplane pilots and biologists disagree about the exact form of continuous thermal chimneys. Pilots have traditionally interpreted thermals as large, tall columns of rising air, usually with a cumulus (white, fluffy) cloud marking the top of the column. In contrast, observers of animal flight find only small, localized thermal chimneys, which usually take the form of dust devils, which are small columnar thermals with intense rotation. Colin Pennycuick, a prolific researcher on bird flight, discounts thermal chimneys and recognizes only ring thermals as sources of large-scale, long-lasting updrafts. In any case, thermals can rise 2 or 3 kilometers above the ground. Also, they tend to increase in size and intensity as they rise, sometimes reaching over 1,000 meters in diameter. Thermals are usually capped by a cloud, because the upper limit of a thermal is set by the altitude where the temperature is low enough to condense water vapor in the thermal, which cools the air and forms a cloud.
As long as the upward speed of the thermal is greater than the sinking speed of a glider, the glider will ascend in the thermal. Of course, the glider will quickly fly out of the thermal if it flies in a straight line, so it must circle to stay in the rising air. (A glider should stay on the inside of the ring, because the air on the outer edge of the ring is actually rolling downward.) Imagine a vulture ascending to 1,500 meters above the ground by circling in a ring thermal. From this height, it will be able to fly out of the thermal and glide for about 30 minutes (traveling over 23 kilometers) before it runs out of altitude and needs to either start flapping, find another thermal, or land. Many soaring birds use just this pattern: climbing up in a thermal, gliding a long distance, then finding another thermal in which to soar. This type of flight is an efficient way to cover long distances at a low energy cost, making it a handy way to migrate or search for food.
Slope soaring is useful when wind blows upward along a slope. The speed of the wind's upward motion can be calculated in the same manner that the sinking speed of a glider is calculated. If the upward speed of this wind is greater than or equal to the sinking speed of a glider, the glider will be able to maintain altitude. Such ridge lift has a characteristic that is both an advantage and a disadvantage: ridge lift is usually predictably tied to a particular slope, so it is easy to find. But it is usable only in that fixed, local area.
at intervals = periodically时不时地
discrete = separate不连续的
prolific = highly productive多产的
adjacent = nearby邻近的
英联全球雅思托福英语Q1 15:01:45
06
The Impact of Industrialization on Labor Systems
工业革命对劳动力系统的影响
重复2016.03.11，2017.07.15上午场，2017.11.11，2018.03.10
工业革命给劳动力带来了很多影响如工具替换了人力，工具的好处是很高效强力并且很精确，能够长时间工作。一些孩子们，虽然在工业早期有时候能够挨近着亲人去工作，也发现他们的工作-家庭关系被重新定义，被工业化的工作从家庭环境中迁出去而重新定义了，在这里的最终解决办法是去把孩子完全拉出劳动力。另一结果是每个人都不是fully skilled，只对某一块熟练所以工厂开除员工很容易成本低，导致人们即使在这么多冲击下也愿意工作。家庭和工作之间隔开的距离，（工人们已经暴露于比他们先前所习惯的更大的场地工作），意味着工人们不得不去应对陌生人了。这样的一系列操作使得进一步促进了工业革命。
components = pieces 组成部分
peak = maximum 最高
gradual = slow 缓慢的
adapt = adjust 适应
07
Pest Control
虫害控制
重复2014.05.25，2017.04.01
对外来引入的非本土害虫，由于没有天敌存在，所以无法根除，对它们人类要采取有效的好虫控制方法。分别从化学法、生物法、综合法三个方面来介绍。
真题原文
Pest Control
Many pest species that are native to North America, such as white-footed mice and ground moles, are more nuisance pests and are usually regulated by native predators and parasites. This situation is not true for nonindigenous pests in North America, such as brown rats and cockroaches. After centuries, it is evident that these pests cannot be eradicated. The best that can be done is to introduce pest control measures that will control their numbers.
And ancient and popular means of pest control is chemical. For example, the Sumerians used sulfur to combat crop pests, and by the early 1800s such chemicals as arsenic were used to combat insect and fungal pests.
However, chemical control has its dark side. Chemical pesticides have many unintended consequences through their effects not just on the target species but on a wide array of nontarget species as well, often eliminating them and thereby upsetting the existing food webs, especially through the suppression of native predator species. The surviving pests then rebound in greater numbers than ever.
Perhaps more insidious is that a pesticide loses its effectiveness because the target species evolves resistance to it. As one pesticide replaces another, the pests acquire a resistance to them all. Some species, notably certain mosquitoes, have overcome the toxic effects of every pesticide to which they have been exposed. Insect pests need not only about five years to evolve pesticide resistance, their predators do so much more slowly. So after the pest develops resistance, pest outbreaks become even more disastrous.
Farmer long ago observed that enemies of pests act as controls. As early as 300 C.E., the Chinese were introducing predatory ants into their citrus orchards to control leaf-eating caterpillars. Insect pests have their own array of enemies in their native habitats. When an animal or plant is introduced, intentionally or unintentionally, into a new habitat outside of its natural range, it may adapt to the new environment and leave its enemies behind. Freed from predation and finding and abundance of resources, the species quickly becomes a pest or a weed. This fact had led to the search for natural enemies to introduce into populations of pests to reduce their populations.
Because the serious pest is usually a nonnative species, biological control involves the introduction of a nonindigenous predator or parasite to control the pest. The introduction of the cactus-eating moth, a native of Argentina, into Australia effectively reduced and controlled the rapidly spreading prickly pear, which had been introduced into Australia in 1901.
But biological control, like chemical control, can backfire. The success of the cactus-feeding moth in controlling prickly pear in Australia encouraged its introduction to several West Indies islands to control prickly pear there. In time the moth made its way to Florida, where it now threatens the existence of several native prickly pear species. The moral is that although using nonindigenous predators as biological controls can be effective, these species possess their own inherent dangers that must be assessed before they are released. They, too, can become alien invaders.
Because chemical, biological, and other methods used individually are obviously not the solution to pest control, entomologists have developed a holistic approach to pest control, called integrated pest management (IPM). IPM considers the biological, ecological, economic, social, and even aesthetic aspects of pest control and employs a variety of techniques. The objective of IPM is to control the pest not at the time a major outbreak but at an earlier time, when the size of the population is easier to control. The approach is to rely first on natural mortality caused by weather and natural enemies, with as little disruption of the natural system as possible, and to use other methods only if they are needed to hold the pest below the economic injury level.
Successful IPM requires the knowledge of the population ecology of each pest and its associated species and the dynamics of the host species. It involves considerable field work monitoring the pest species and its natural enemies by such techniques as egg counts and the trapping of adults to acquire information to determine the necessity, timing, and intensity of control measures. These control measures must be adjusted to the situation, which may vary from one location to another. The intensity of control or no control is based on the degree of pest damage that can be tolerated, the costs of control, and the benefits to be derived.
08
Evidence of Zooxanthellae in Fossilized Corals
虫黄藻在石化的珊瑚里的证据
重复→2018.03.10
本文介绍了虫黄藻在石化的珊瑚里的证据且提到了珊瑚和Z的一种寄生关系。珊瑚提供保护，z提供光合作用产生的二氧化碳，但寄生珊瑚不能在太低温度或太深的海底因为光照不到——z光合作用也就不行了。但有些也不是寄生的，判断寄生方法是同位素，z需要C12而非C13。多余C13排放被珊瑚吸收，所以C13多的珊瑚就存在寄生关系。此外在判断化石生长速度时可以用X ray来测定出类似于树木年轮一样的记录，有些珊瑚不存在寄生关系仍然可以生存是因为海水深度的变化并不会影响珊瑚的生长速度。
09
南亚昆虫的翅膀
10
人口发展与食物供给之间的关系
第一段：中国的人口有很大的增长，因为sweet potato和另外两种食物的出现，它们可以在非常干旱的条件下生长，rice却不行，而且可以一年种植两三次；
第二段：欧洲人口也有增长；
第三段：技术方面的发展促进这种增长，介绍了两个技术；
第四段：但是食物的增长却没办法keep in pace with人口的增长。
11
婴儿的早期行为
whether instinct or learned（两个对立流派的观点，对比结构证明类文章）
12
Dinosaurs and Parental Care
恐龙的亲本养育
重复2018.07.01,2015.02.01，2014.08.23
alleged = supposed 所谓的
controversial = debatable 有争议的
inconclusive = not decisive 无定论的
13
Logging
树木砍伐对生态的影响
以前美洲欧洲等大陆存在着许多的森林，但是现在只有温带才有大量的森林，而热带的森林正在越来越少。原因之一就是人类的伐木行为。人们的伐木行为通常都有一定的偏好，专门爱砍伐某种特定的树木，这种行为会影响植物的多样性，进而影响依赖这种树木生存的动物，所以还会影响动物的多样性。接着文章讲述了伐木对整体环境的影响，伐木带来了水土流失（faster runoff），水土流失导致土壤的颗粒进入到河流小溪里，这样就影响了鱼类的产卵，直接导致了鱼的数量的减少。另外讲了木来来说最经济划算的一种伐木方式，但是这种方式也存在以上的种种弊端，有一个解决办法就是在临河的斜坡上保留一片不被砍伐的树木带，这些树木既可以保护河堤，而且树木的阴影可以使得河面的温度相对较低，这样又保护了鱼的生存环境。
14 19世纪的印象派艺术
回忆11：
阅 读
寒假之后的第一场托福考试，阅读部分，11-16年老题出现6篇，17-18年次新题出现3篇，考过的题目占到所有考察篇章的四分之三，并且有更多重复18年考过试题的趋势，所以，建议备考的同学，一定要去熟悉18年所有考过的阅读篇章，哪怕是话题有所知晓，尽可能早上手真题篇章刷题。
词汇题难度依旧维持之前的水平不变。
阅读篇章
A tauemerald (Hemicordulia tau) dragonfly has flight muscles attacheddirectly to its wings.
Early life-forms and Earth'satmosphere （14年6月15日考题，介绍早期大气在地球生命诞生发展过程中的作用。）
Dinosaurs and Parental Care（15年2月1日和18年8月26日考题。）
Gliding and Soaring（15年9月12日考题）
Bird Songs（15年1月11日考题，对比野外长大和隔离长大的鸟，来看鸟是如何学会鸣叫的，有天生也有胡天因素。）
沙漠里动植物的生活（16年10月16日考题，可以参考TPO26-2，Survival of Plants and Animals in Desert Conditions。）
工业化industrialization对labor system的影响（16年3月11日考题，文章内容可以参考OG2 Artisans andIndustrialization）
Evidence of Zooxanthellae in FossilizedCorals（18年3月10日考题，珊瑚化石中虫黄藻的证据）
Theories of Megafauna Extinction（继恐龙灭绝之后的又一年度灭绝话题。18年6月30日、7月1日和3月11日都考过The Australian Megafauna Extinctions，主要讨论环境以及人类因素，小型动物对大型动物的生存优势）
Insect Wings（17年10月29日考题，昆虫翅膀。P1引入话题，翅膀化石，引发很多猜测speculation；P2讲了原始翅膀protowings，提出了一个theory，讲了翅膀的作用；P3指出上一段理论问题，说protowing需要和身体连接hinged，并且需要有肌肉控制翅膀的拍动，所以提出了另外一个理论解释翅膀的起源。）
Changes in the Amount of Forest onthe Great Plains（16年9月25日和17年11月18日考题，从forest到grassland的成因；气候变化，干旱导致grassland经常会有fire，导致森林减少，其中也有人工防火，为了buffalo。但是，随着温室气体二氧化碳浓度增加，trees又变多了。）
Agriculture in Early modern world （中国玉米和大米的增加，促进了人口扩张，比如可以在paddies反复种植rice，一年中可以多次丰收。后来传到欧洲，也为欧洲人口提供大量食物，举例England。）
19世纪的印象派艺术
城市形成的各种原因
回忆12：
综合写作
Titan 上 unexplained的特征。
阅读：
1：Titan上第一个unexplained的特征是不寻常的轨道。
2：Titan上第二个unexplained的特征是有很多的洼地。
3：Titan上第一个unexplained的特征是有很多的沙丘。
听力：反驳阅读。
1：Titan 不是一个独立的星球，是有几个小的星球不断碰撞组成的，所以从圆形变成了椭圆形。
2：Titan的洼地形成和地球差不多，在地球上有许多岩石的物体，会被液体分解，所以Titan有降雨量，就会形成洼地。
3：Titan上的风是eastward，真正影响沙丘运动的不是风，而是比风强十倍的飓风。
话题分类：“对立”题型
解题思路：综合写作基本框架思路。注意转述内容时侧重于听力部分，且以表意清晰为上。
参考范文：
Both the author and the lecturer concentrate on the unexplained features.The reading passage asserts that there are three existing on the Titan. However,the professor in the lecture totally refutes all the passage's viewpoints.
Firstly, even though the writer claims that the orbit tend to be unusual on the Titan, the speaker discredits this by arguing that the Titan is not asingle planet, because it consists of several moons and they continue to collide and then merge together. Therefore, it is likely to form a ellipticalorbit rather than circular one.
Furthermore, despite the statement in the reading passage that there aremassive depressions that are observed on the Titan, the professor contends that the process of forming depressions is extremely similar to ones on the earth.The speaker further explains that many rocky objects on the earth are often dissolves by liquid, which undeniably results in a great deal of depressions.Naturally, if there is rainfall on the planet, it will form depression to some extent.
Finally, the author states that it is less likely to form sand dunes onthe Titan. The lecturer counters that the formation of sand dunes is due to eastward hurricanes instead of westward wind mentioned in the reading passage. Also, the professor advances the argument, saying that the true cause is hurricanes effect that is far stronger, which is unlike the power of this kind of wind. For these concerns, these three features on the Titan can be explained.
In brief, the writer and the speaker contradict each other on the formation of these features on the Titan.
本篇范文可以借鉴的模板：
Both the author and the lecturer concentrate on___________. The reading passage asserts that_____________.However, the professor in the lecture totally refutes allthe passage's viewpoints.
Firstly, even though the writer claimsthat_______________, the speaker discredits this by arguing that____________________.
Furthermore, despite the statement in the reading passagethat ____________,the professor contends that______________________.The speaker further explains that____________.
Finally, the author states that_____________. The professor advances the argument, saying that__________.
In brief, the writer and the speaker contradict each other on_______________.
独立写作
It is difficult for teachers to be both popular(well-liked) and effectively in helping students’ study.
话题分类：教育类话题
解题思路：本篇范文从同意的角度，分论点可以参考一个从教学难入手去写，一个从受欢迎难入手去写。
参考范文：
Traditionally, teachers aremainly responsible for imparting their students with academic knowledge effectively, which aims to achieve more grades in a great many examinations, but a soaring number of students, meanwhile, start to focus more on whether their teachers are popular among them besides their academic capacity. This phenomenon has already been prevalent among educational authorities orindividual schools. However, from my perspective, it is relatively difficultfor teachers to achieve this point in reality.
Contrary to the popular belief that teachers could easily gain popularity among students in one class, the majority of teachers, in turn, are able to achieve this aim completely. Apparently, almost every teacher possesses their own teaching style, due to their own traits of character or unique life experience, and express it inclass. Meanwhile, different educational backgrounds enable students to develop their own cognitive competence, which means they form a standard of popularity differing from others. Therefore, the teaching style of one teacher, to acertain extent, could attract a few or over half students in a same class,whereas he might not draw attention from all students in his class, though he could impart knowledge effectively.
Furthermore, the complexity and diversity in the modern society may be another major contributor. To further demonstrate, more demanding requirement concerning teachers as well as teaching methodology from students owes much to information explosion. By thatI mean, those students who know how to search for the valuable information available on the Web can browse for more detailed information about the subjects discussed in class, dimensional understanding of the current issues,since so great a variety of related information can be accessed by some powerful search engines such as Google, or Baidu. However, these merely couldbe achieved from teachers during the class. Under it’s overwhelming impact,teachers are supposed to master more professional knowledge that cannot begained from the Internet and more effective approaches to improve the efficiency of education. Naturally, they are likely to have more difficulty inassisting students in studying, not to mention the popularity.
Inconclusion, even if the preference among students can be regarded as the powerful backup of education rather than its unimportance accessory, it is noteasier for teachers to earn a good reputation and perform well in teaching harmoniously.
Titan 上 unexplained的特征。
阅读：
1：Titan上第一个unexplained的特征是不寻常的轨道。
2：Titan上第二个unexplained的特征是有很多的洼地。
3：Titan上第一个unexplained的特征是有很多的沙丘。
听力：反驳阅读。
1：Titan 不是一个独立的星球，是有几个小的星球不断碰撞组成的，所以从圆形变成了椭圆形。
2：Titan的洼地形成和地球差不多，在地球上有许多岩石的物体，会被液体分解，所以Titan有降雨量，就会形成洼地。
3：Titan上的风是eastward，真正影响沙丘运动的不是风，而是比风强十倍的飓风。
话题分类：“对立”题型
解题思路：综合写作基本框架思路。注意转述内容时侧重于听力部分，且以表意清晰为上。
参考范文：
Both the author and the lecturer concentrate on the unexplained features.The reading passage asserts that there are three existing on the Titan. However,the professor in the lecture totally refutes all the passage's viewpoints.
Firstly, even though the writer claims that the orbit tend to be unusual on the Titan, the speaker discredits this by arguing that the Titan is not asingle planet, because it consists of several moons and they continue to collide and then merge together. Therefore, it is likely to form a ellipticalorbit rather than circular one.
Furthermore, despite the statement in the reading passage that there aremassive depressions that are observed on the Titan, the professor contends that the process of forming depressions is extremely similar to ones on the earth.The speaker further explains that many rocky objects on the earth are often dissolves by liquid, which undeniably results in a great deal of depressions.Naturally, if there is rainfall on the planet, it will form depression to some extent.
Finally, the author states that it is less likely to form sand dunes onthe Titan. The lecturer counters that the formation of sand dunes is due to eastward hurricanes instead of westward wind mentioned in the reading passage. Also, the professor advances the argument, saying that the true cause is hurricanes effect that is far stronger, which is unlike the power of this kind of wind. For these concerns, these three features on the Titan can be explained.
In brief, the writer and the speaker contradict each other on the formation of these features on the Titan.
本篇范文可以借鉴的模板：
Both the author and the lecturer concentrate on___________. The reading passage asserts that_____________.However, the professor in the lecture totally refutes allthe passage's viewpoints.
Firstly, even though the writer claimsthat_______________, the speaker discredits this by arguing that____________________.
Furthermore, despite the statement in the reading passagethat ____________,the professor contends that______________________.The speaker further explains that____________.
Finally, the author states that_____________. The professor advances the argument, saying that__________.
In brief, the writer and the speaker contradict each other on_______________.
独立写作
It is difficult for teachers to be both popular(well-liked) and effectively in helping students’ study.
话题分类：教育类话题
解题思路：本篇范文从同意的角度，分论点可以参考一个从教学难入手去写，一个从受欢迎难入手去写。
参考范文：
Traditionally, teachers aremainly responsible for imparting their students with academic knowledge effectively, which aims to achieve more grades in a great many examinations, but a soaring number of students, meanwhile, start to focus more on whether their teachers are popular among them besides their academic capacity. This phenomenon has already been prevalent among educational authorities orindividual schools. However, from my perspective, it is relatively difficultfor teachers to achieve this point in reality.
Contrary to the popular belief that teachers could easily gain popularity among students in one class, the majority of teachers, in turn, are able to achieve this aim completely. Apparently, almost every teacher possesses their own teaching style, due to their own traits of character or unique life experience, and express it inclass. Meanwhile, different educational backgrounds enable students to develop their own cognitive competence, which means they form a standard of popularity differing from others. Therefore, the teaching style of one teacher, to acertain extent, could attract a few or over half students in a same class,whereas he might not draw attention from all students in his class, though he could impart knowledge effectively.
Furthermore, the complexity and diversity in the modern society may be another major contributor. To further demonstrate, more demanding requirement concerning teachers as well as teaching methodology from students owes much to information explosion. By thatI mean, those students who know how to search for the valuable information available on the Web can browse for more detailed information about the subjects discussed in class, dimensional understanding of the current issues,since so great a variety of related information can be accessed by some powerful search engines such as Google, or Baidu. However, these merely couldbe achieved from teachers during the class. Under it’s overwhelming impact,teachers are supposed to master more professional knowledge that cannot begained from the Internet and more effective approaches to improve the efficiency of education. Naturally, they are likely to have more difficulty inassisting students in studying, not to mention the popularity.
Inconclusion, even if the preference among students can be regarded as the powerful backup of education rather than its unimportance accessory, it is noteasier for teachers to earn a good reputation and perform well in teaching harmoniously.
回忆13：
口语
Task 1
重复17年10月28日
1. which of the following do you think is most needed tobe a government leader?
1）military 2）law 3）business
Please include details and examples in your response
参考范文：
Among the three choices, I think people who involves in the business field will become the most potential government leader. First, a crucial fact is that business man are rich. If they wanna to start some projects, it is pretty easier to collect money or use their own money. Second, after years of accumulation in the business area, they gain a lot of friends who spread in different fields,which means that they will get a lot of help. Take Jack Ma for example, he is the riches guy in china and he knows alot government officials. It is much easier to become a leader if he would like to switch business to politics.
Task 2
There is a policy that parents should not beallowed to see children's grades without their permission. Do you agree or disagree?
参考范文：
In terms of children's grade, I think it depends on what kind of ages they are. If they're pretty young and they're not mature.I think it's necessary for parents to guide their kids, telling them what is wrong and right. If they're doing good in school, mom and dad could give them some reward to encourage them. If they're not good, parents could supervise them and give them more suggestions. But for students who are mature enough, like college students. If they fail the exam, they probably will know what to do and how to prepare in order to do better score next time. For this point, parents’ concern seems to be helpless.
回忆14：
回忆15：
2019年1月26日托福考试总体反馈-2019年1月26日托福命中ABC卷多篇阅读真题原题（大量阅读旧题），命中独立和综合大作文真题原题（都是旧题），命中口语四部分和听力四篇旧题，听力最难，CPU资料阅读、写作、听力、口语等全面大中，全面开花！今天的托福考试，依然是几套试卷组合，这种模式会一直持续下去。今天托福考试几大特点：（1）听力、口语、写作、阅读老题重复量巨大。（3）在大部分考试中，写作听力一直是四项难度最大，并且对话难度超过讲座）（4）独立和综合写作重复老题，是我们TOEFL CPU资料里面的。今天大部分题目都在我们CPU资料原题命中！祝贺CPU会员将出现不少100-110分以上托福天才！今天听力阅读里大多是老题，仍然大量重复2015-2018年的老题，尤其是我们CPU托福资料的真题。今天口语和写作也是老题居多。ETS今年虽然在考试形式上变化很多，但其实使用的新题非常少，大都是在重复2014-2018年大陆考过的新题。这一方面说明，ETS出题成本太高（80万美金一套），所以出题量小。另一方面说明，托福考试的整体趋势还是稳定的。形式上的变化（多套试卷，阅读加试，听力非经典加试），并不能改变这个考试的内在。今天听力，口语，阅读和写作都重复老题。总体反馈请复制链接进入http://bbs.ieltstofelglobal.com/thread-243203-1-1.html和http://bbs.ieltstofelglobal.com/thread-243203-1-1.html和http://bbs.ieltstofelglobal.com/forum-133-1.html
特别提醒：托福考试几十多年来，有非常严格的规律性和出题思路。全世界有6到10个托福大考区，而只有一个美国托福考试中心几个人在出题，每个考区每个月要出2-4份考卷，一个月出12-24份考卷，考官如何保证达到难度一样呢，如何保证新题难度、准确度和评价机制公平呢，所以只能是几十年来托福真题题库旧题目的有效组合，新题不能超出10%。事实上每份托福真题卷子都是80%-90%以上旧题原题真题。近年来，阅读几套卷里大多是老题，ETS今年虽然在考试形式上变化很多，但其实使用的新题非常少，大都是在重复2014-2018年大陆考过的老题。这一方面说明，ETS出题成本太高（80万美金一套），所以出新题量小。另一方面说明，托福考试的整体趋势还是稳定的。形式上的变化（多套试卷，阅读加试，听力非经典加试），并不能改变这个考试的内在。除了阅读之外，听力，口语和写作都大部分是重复老题。多年托福考官和专家Edward老师非常熟悉托福出题规律和听说读写题库出题组合卷子的秘诀， CPU资料因此而诞生！具体请阅读http://bbs.ieltstofelglobal.com/thread-231387-1-1.html