原文：
You should spend about 20 minutes on Question 14-26 which are based on Reading Passage below.
A
The forest canopy-the term given to the aggregated crowns of trees in a forest-is thought to host up to 40 per cent of all species, of which ten per cent could be unique to the forest roof. "We're dealing with the richest, least known, most threatened habitat on Earth," says Andrew Mitchell, the executive director of the Global Canopy Programme/ a collection of groups undertaking research into this lofty world. "The problem with our understanding of forests is that nearly all the information we have has been gleaned from just two meters above the soil, and yet we're dealing with trees that grow to heights of 60 meters, or in the case of the tallest redwood 112 meters. It's like doctors trying to treat humans by only looking at their feet."
B
Tropical rainforest comprises the richest of ecosystems, rivalled only by coral reel for its diversity and complex interrelationships. And a great deal of that diversity lives up in the canopy-an estimated 70-90 per cent of life in the rainforest exists in the trees; one in ten of all vascular plants are canopy dwellers; and about 20-25 per cent of all invertebrates are thought to be unique to the canopy.
C
The first Briton to actually get into the canopy may have been Sir Francis Drake who, in 1573, gained his first glimpse of the Pacific Ocean from a tall tree in Darien, Panama. However, the first serious effort to reach and study the canopy didn't begin until 1929. The Oxford University Expedition to British Guiana, led by Major RWG Hingston, still ended up help of locals when it came to building an observation platform. It was a successful expedition all the same, despite the colony's acting governor getting stuck high up on a winched seat during a visit. In terms of canopy access, the French have proved themselves to be excellent innovators, taking things further with the development of 'lighter-than-air platforms -balloons and related equipment, to you and me. Francis Halle; from the Laboratoire de Botanique Tropicale at Montpellier University took to a balloon in the mid-1980s in order to approach the canopy from above. His work in French Guiana was inspired by the use in Gabon of a tethered helium balloon by Marcel and Annette Hladick. Halle went one further by using a small purpose-built airship-a cigar-shaped balloon with propellers to aid manoeuvrability. "We suddenly had a mobile system that could move around the treetops; there was no other means of doing this," says Mitchell.
D
From this, two balloon-dependent features have developed: the radeau or raft, and the luge or sledge. The raft is a 'floating' platform, employed by French academics Dany Cleyet-Marrel and Laurent Pyot and is essentially an island in the treetops. Made of kevlar mesh netting and edged with inflated neoprene tubes, it rests on top of the canopy, allowing sampling (mostly of plants and insects) to take place at the edges of the platform, and can stay in position for several days. The luge, on the other hand, is an inflated hexagon similar to a traditional balloon basket but with a hole in the bottom covered with Kevlar mesh. Such techniques aren't without their problems, however, "balloons can cover larger areas, especially for collection purposes, but they are extremely expensive- Jibe raft alone cost 122,000 [euro] (86,000 [pounds sterling]) in 2001], nut very effective because you can only reach the tops of the trees, and are highly dependent on the weather, " says Dr Wilfried Morawetz, director of systematic botany at the University of Leipzig. “Balloons can usually only be used in the early morning for two to four hours. Last time, we could only fly three times during a whole week." Given these factors, it comes as no surprise that operations involving these balloons numbered just six between 1986 and 2001.
E
Smithsonian Tropical Research Institute in Panama. Smith had the idea of using a static crane to get into the treetops. Un-tethered balloons may allow widely distributed sites to be sampled, but cranes allow scientists to study an area of at least a hectare from soil to canopy throughout the year, year after year. "Cranes beat any other access mode. They are cheap, reliable and fast. In two minutes I can reach any point in our forest, which is essential for comparative measurements across species," says Professor Christian Korner of the University of Basel. Korner is using a static crane in a unique carbon dioxide-enrichment experiment in Switzerland, in an attempt to discover how forests might respond to the global increase in atmospheric carbon dioxide (see Swiss canopy-crane carbon experiment, right). For reasons of convenience, cranes are generally situated close to cities or a research center. Leipzig University has a crane not far from the town, the Location allowing scientists to study the effect of city pollutants on forests. In order to increase the amount of canopy a crane can access, some have been mounted on short rail tracks. In "1995, Dr Wilfried Morawetz was the first to use this technique, installing a crane on 150 meters of track in Venezuelan rainforest. “In my opinion, cranes should be the core of canopy research in the future," he says.
F
It appears that the rest of the scientific community has now come around to Mitchell's way of thinking. "I think most scientists thought him mad to consider such a complex field station at first," says internationally respected 'canopist' Meg Lowman, the executive director of the Marie Selby Botanical Gardens. "However, we've all come to realize that a combination of methods, a long-term approach to ecological studies and a collaborative approach are the absolute best ways to advance canopy science. A permanent canopy field station would allow that to happen." With A dedicated group of canopy scientists working together and a wide range of tools available for them to get into the treetops, we're now finally on our way towards a true understanding of the least-known terrestrial habitat.
Questions 14-18
The reading Passage has seven paragraphs A-F
Which paragraph contains the following information?
Write the correct letter A-F, in boxes 14-18 on your answer sheet
14. The Scientific significance for committing canopy study.
15. The first academic research attempt mentioned to get to the top canopy.
16. The overview idea of forest canopy and the problem of understanding the forests.
17. A recognition for a long term effect and cooperation.
18. An innovation accessing to treetop which proved to be an ultimate solution till now.
Questions 19-22
Summary
Complete the following summary of the paragraphs of Reading Passage, using No More than Two words from the Reading Passage for each answer. Write your answers in boxes 19-22 on your answer sheet.
Scientists keep trying new methods to access to the canopy of the treetop. Though early attempt succeeded in building an observation platform yet the help from the 19 was imperative; further innovators made by the French who built a platform with equipment by using 20 . Later, the ‘floating’ platform of 21 is serving as an island in the treetops. Then finally, there came the next major breakthrough in Panama. Scientists applied 22 to access to the treetops, which are proved to be the center of canopy research in today and in the future.
Questions 23- 27
Use the information in the passage to match the category (listed A-F) with opinions or deeds below. Write the appropriate letters A-F in boxes 23-27 on your answer sheet.
NB you may use any letter more than once
A. Sir Francis Drake
B. Wilfried Morawetz
C. Dany Cleyet-Marrel
D. Francis Halle
E. Christian Korner
F. Alan Smith
23. Scientist whose work was inspired by the method used by other researchers.
24. Scientist who made a claim that balloon could only be used in a limited frequency or time.
25. Scientist who initiated a successful access mode which is cheap and stable.
26. Scientist who had committed canopy-crane experiment for a specific scientific project.
27. Scientist who initiated the use of crane on the short rail tracks.
参考译文：
树冠的研究者
A
森林树冠层是用来描述森林中所有树冠总和的术语，是超过40%生物物种的栖息地，其中10%的物种是只生活在树冠上的。Global Canopy Programme是专门研究树冠的组织，它的执行主席Andrew Mitchell说道：“我们正在研究地球上最丰富，最鲜为人知但是 又最受威胁的栖息地。我们对森林认识的问题在于几乎所有我们收集的信息只是从距离地面2米的地方获得的，但是我们却要以此研究关于距离地面60米髙的树，或是最高达112米的红木这样的树木的问题。这就好比医生只能通过看病人的脚来治愈病人。”
B
热带雨林包含最丰富的生态系统，从生物多样性和生物之间关系的复杂性上来讲，只有珊瑚礁可以与之媲美。而其中大部分的多样性的生物都居住在树冠上，据估计雨林中70%-90%的生物居住在树上，有十分之一的导管植物是生长在树冠层，大约20%-25%的无脊椎动物只生活在树冠层。
C
第一个真正意义上进入树冠层进行研究的英国人是Sir Francis Drake，他在1573年在巴拿马的Darien的一刻高树第一次看到了太平洋。但是第一个真正意义上的关于树冠的研究指导1929年才开始。Major RWG Hingston领导的牛津大学科考队赴英属圭亚那进行考察，最终在需要建造一个观察平台时，他们还是向当地人进行了求助。这次科考总的来说还是很成功的，尽管代理领导者在坐着轿子参观的过程中被卡到悬在空中。就到达树冠这个层面而吉，法国人可以说是优秀的创新者，他们通过比空气还轻的平台也就是气球和相关的设备来运送东西。来自Montpellier大学热带植物研究所的Francis Halle在1980年代中期通过一个气球从空中到达树冠。他在法属圭亚那的工作收了Marcel和Annette Hladic在加蓬共和国氦气球的启发。Halle更近一部，他乘坐了专门建造的一个小型的飞行器——长得像雪茄形状的气球，是靠螺旋桨来增加机动性的。Mitchell说道：“我们突然有了一个可移动的系统来在树梢附近活动，除此别无他法。”
D
自此以后，两个以来气球的工具就产生了：筏子或是雪橇，筏子是“漂浮着的平台”，被法国学者Danny Cleyet—Marrel和Laurent Pyot应用在树顶的一个小岛上，是用橡胶渔网边缘配上充气的氯丁橡胶管子做成的。这个小筏子停留在树冠层的顶部，这样可以让生物抽样(主要是植物和昆虫)可以在平台的边缘停留数日。在另一方面，雪橇呈充气六边形，和传统的气球篮子相似，在底部的中间有一个洞，上面覆盖着橡胶网，当然这种技术不是完美的。莱比锡大学系统植物研究所主任Dr Wilfried Morawets说道：“气球可以覆盖更大的区域，尤其是手机信息的时候，但是它们的造价非常高，Jibe筏子造价122,000欧元(约合86000英镑，按2001年的汇率)虽然这种方式很有效，但是只能是研究人员到达顶部并且对天气的依赖性很强。气球只能在淸早使用2-4小时，上周整整一周因为天气原因我们只能出去考察3次。”鉴于以上因素，就不难理解为什么在1986年和2001年间只存六次研究活动采用气球。
E
接下来另一个重要的创新来自巴拿马Smithsonian Tropical Research Institute的Alan Smith，他是采用一个静止的起重机来到达树冠。没有绳子拴着的气球能够大范围地采集样本，但是起重机可以让科学家年复一年地通年集中研究一公顷的范围内从土壤到树冠。Basel大学的教授Christian Korner认为“起重机比其他任何一种方法都要好，它们好，它们又便宜有可靠而且快速。我可以在两分钟之内到达想要到达的森林的任何位置，这对于物种间的比较研究至关重要。” Christian Korner在瑞士用充满二氧化碳的空气中用起重机进行一个实验。试图揭开森林将如何应对全球二氧化碳含量上升。为了简便起见，起重机一般都安置在靠近城市或是研究中心，莱比锡大学在离城镇不远的地方就有一个研究用的起重机，该地点可以让研究者对污染物对森林的影响进行研究。为了增加起重机能到达的树冠的数量，一些起重机放在短的铁轨上。在1995年，Dr Wilfried Morawets是第一个采用这样技术的人，在Venezuelan雨林假期了150米的轨道。他说道：“在我看来，起重机将是未来研究树冠的核心工具。”
F
似乎进行树冠研究的其他人和Mitchell的观点一样，被组委“树冠学家”的Madie Selby Botanical Gardens的执行主任Meg Lowan说道：“期初许多科学家肯定认为Mitchell疯了才会想到建这样一个复杂的实地观察站。但是我们逐渐都点识到，将不同方法进行组合，从而能够用长期合作的方法来进行生态研究是推进树冠研究最好的方法。一个永久的树冠研究站能够做到这一点。”一群致力于研究树冠的科学家通力合作，运用一系列的工具到达树顶，从而可以真正了解最不为人知的陆地柄息地—树冠。”
答案：
