雅思阅读部分
第一篇:摩斯密码Morse code A Morse code is being replaced by a newsatellite-based system for sending distress calls at sea. Since 1992 countriesaround the world have been decommissioning their Morse equipment with similar(if less poetic) sign-offs, as the world,s shippingswitches over to a new satellite- based arrangement, the Global MaritimeDistress and Safety System. The final deadline for the switch-over to GMDSS isFebruary 1 st, a date that is widely seen as the end of an era. For althoughdots and dashes will not die out altogether — theywill, for example, continue to be used by amateur radio operators, spies, andsome members of the armed forces — theswitch to GMDSS marks the end of the last significant international use ofMorse.
B Thecode has, however, had a good history. Appropriately for a technology commonlyassociated with radio operators on sinking ships, the idea of Morse code issaid to have occurred to Samuel Morse while he was on board a ship crossing theAtlantic. At the time Morse was a painter and occasional inventor, but whenanother of the ship’s passengers informed him of recentadvances in electrical theory, Morse was suddenly taken with the idea ofbuilding an electric telegraph. Other inventors had been trying to do just thatfor the best part of a century. Morse succeeded and is now remembered as 'thefather of the telegraph’ partly thanks to his single mindedness — it was 12 years, for example, before he secured moneyfrom Congress to build his first telegraph line 一 but alsofor technical reasons.
C Comparedwith rival electric telegraph designs, Morse’s designwas very simple: it required little more than a ‘key’ (essentially, a spring-loaded switch) to sendmessages, a clicking ‘sounder’ toreceive them, and a wire to link the two. But although Morse’s hardware was simple, there was a catch: in order touse his equipment, operators had to learn the special code of dotsand dashes.Originally, Morse had not intended to use combinations of dots and dashes torepresent individual letters. His first code, sketched in his notebook duringthat transatlantic voyage, used dots and dashes to represent the digits 0 to 9.Morse’s idea was that messages would consist ofstrings of numbers corresponding to words and phrases in a special numbereddictionary. But Morse later abandoned this scheme and, with the help of anassociate, Alfred Vail, devised the Morse alphabet, which could be used tospell out messages a letter at a time in dots and dashes. At first, the need tolearn this complicated-looking code made Morse’stelegraph seem impossibly tricky compared with other, more user-friendlydesigns. Cooke’s and Wheat stone’s telegraph, for example, used five needles to pickout letters on a diamond-shaped grid. But although this meant that anyone coulduse it, it also required five wires between telegraph stations. Morse’s telegraph needed only one.
D Aselectric telegraphy took off in the early 1850s, the Morse telegraph quicklybecame dominant. It was adopted as the European standard in 1851, allowingdirect connections between the telegraph networks of different countries.(Britain chose not to participate, sticking with needle telegraphs for a fewmore years. ) By this time Morse code had been revised to allow for accents andother foreign characters, resulting in a split between American andInternational Morse that continues to this day.
E Oninternational submarine cables, left and right swings of a light-beam reflectedfrom a tiny rotating mirror were used to represent dots and dashes. Meanwhile adistinct telegraphic subculture was emerging, with its own customs andvocabulary, and a hierarchy based on the speed at which operators could sendand receive Morse code. First-class operators, who could send and receive atspeeds of up to 45 words a minute, handled press traffic, securing thebest-paid jobs in big cities. At the bottom of the pile were slow,inexperienced rural operators, many of whom worked the wires as part-timers. Astheir Morse code improved, however, rural operators found that their new-foundskill was a passport to better pay in a city job. Telegraphers soon swelled theranks of the emerging middle classes. Telegraphy was also deemed suitable workfor women. By 1870, a third of the operators in the Western Union office in NewYork,the largest telegraph office in America,were female.
F Ina dramatic ceremony in 1871, Morse himself said goodbye to the global communityof telegraphers he had brought into being. By the time of his death in 1872,the world was well and truly wired: more than 650, 000 miles of telegraph lineand 30, 000 miles of submarine cable were throbbing with Morse code; and 20,000 towns and villages were connected to the globalnetwork. Just as the Internet is today often called an 'informationsuperhighway‘, the telegraph was described in its day asan ‘instantaneous highway of thought’.
G But by the 1890s the Morse telegraph‘ s heyday as a cutting-edge technology was coming toan end, with the invention of the telephone and the rise of automatictelegraphs, precursors of the teleprinter, neither of which required specialistskills to operate. Morse code, however, was about to be given a new lease oflife thanks to another new technology: wireless. Following the invention ofradiotelegraphy by Guglielmo Marconi in 1896, its potential for use at seaquickly became apparent. For the first time, ships could communicate with eachother, and with the shore, whatever the weather and even when out of visualrange. In 1897 Marconi successfully sent Morse code messages between a shorestation and an Italian warship 19km (12 miles) away. The first sea rescue aftera distress call sent by radiotelegraph took place in 1899, when a lightship inthe Dover Straits reported the grounding of Elbe, a steamship.
H After nearly 170 years, Morse code will finally slip beneath the waves.Over and out as communications protocols go, Morse has lasted a surprisinglylong time--admittedly with a few tweaks here and there. There classical dotsand dashes will not die out altogether--they will, for example, continue to beused by amateur radio operators, spies, and some members of the armed forces.
答案:
27 . ii 28 .vii 29. iv 30. i 31. iii 32: ix
33. vi 34 Not Given 35.True 36.True
37. Not Given 38.Not Given 39.B 40.C
第二篇:双语使用情况
第三篇:新西兰天气