大学英语四级模拟试题(7)

　　Passage 3 American Scientists have developed a new kind of wire that can carry telephone messages for long distances. The new fluoride glass wire, or optical fibre, is a major improvement over the optical fibres now used in many modern communication systems.
　　Present optical fibres are made from silica glass. They are not costly to produce, but the signals carried by these silica optical fibres weaken very quickly. A repeater device must be built every 50 kilometers to increase or amplify the signals' strength. Such repeater devices are costly and they need electrical power. This creates special problems for optical fibre systems that cross oceans. Long copper wires are needed to carry electricity from shore to repeater devices under the ocean. Repairing the underwater repeaters is costly and takes much time.
　　The new fluoride optical fibre is only a little bigger around than a human hair, yet each could carry 10,000 telephone messages at one time for thousands of kilometers. Traditional copper telephone wires can carry only 4 messages. And unlike present silica optical fibres, the new fluoride glass wires could carry messages for thousands of kilometers with very few, if any, repeater devices.
　　The navy scientists developed the new optical fibres for systems that cross oceans, but they said there also would be many other uses for the fluoride glass wires. The new optical wires could be used for long-distance temperature sensing devices. They could be used in some medical operations.
　　Scientists caution that the new fluoride optical fibre still is only experiment. Researchers have not yet been able to make long tiny wires from fluoride glass.
　　31. Which of the following statements is not true？
　　A. Silica optical fibres are not expensive to produce. B. Signals carried by silica optical fibres are rather weak. C. Additional devices are needed for present optical fibre/fiber systems. D. Repeaters bring about special problems for transoceanic communications.
　　32. The major advantage of fluoride optical fibres/fibers over silica wires is that fluoride glass . A. needs much fewer, if any, repeaters B. carries more telephone messages C. is less costly to produce D. is tinier
　　33. The new glass wire was designed for . A. communications systems that cross oceans B. long-distance temperature sensing devices C. some medical operations D. replacing silica optical fibres
　　34. The fluoride optical fibres is experimental because the new glass wire made so for . A. is quite expensive B. can not yet carry enormous messages C. still needs repeaters D. is not long enough
　　35. The author's main idea is that . A. present optical fibres are made from silica glass B. silica optical fibres need repeaters to amplify the signals carried C. American scientists have developed a new glass wire to carry long-distance telephone messages D. the new optical fiber had many uses
　　Passage 4 There is no doubt that adults, and even highly educated adults, vary greatly in the speed and efficiency of their reading. Some proceed very slowly throughout； others dash along too quickly and then have to regress. Poor readers in particular may lack the ability to vary their manner of reading according to the type of reading matter and to their intentions in reading it. A good reader can move at great speed through the text of a novel or similar light reading matter. He may be able to skim a page, picking up a word or two here and there, and gain a general idea of what the text is about without really reading it. In reading more difficult material, with the intention of taking in the whole of it, he will proceed more slowly, but even then he will vary his pace, concentrating on the key words and passages, perhaps re-reading them several times and pass more quickly over the remainder. A less efficient reader tends to maintain the same speed whatever the material he reads. Consequently, even light reading matter gives him little pleasure because he reads so slowly. But this pace may be too fast for really difficult material which requires special concentration at difficult points. A type of reading which necessitates careful attention to detail is proofreading, in which the reader, in order to detect misprints in a sample print, has to notice not so much the meaning of what he reads as the exact shape and order of letters and words in the text. This is extremely difficult for most people, since they are accustomed to overlooking such details. In fact, considerable practice is required to practise this task efficiently and it can be done only be reading very slowly, and by paying comparatively little attention to the general meaning of the text.
　　36. The author claims that there is a difference in reading speed . A. among readers who have different experience. B. among all the readers. C. between the poorly educated and the highly educated. D. among the highly educated people
　　37. A good reader is a reader who . A. concentrates on the wonderful part of the article B. always reads slowly and carefully C. changes his speed according to the kind of text D. changes his speed according to the interesting of the text.
　　38. The author says that when reading a novel, a good reader can quickly read . A. every part of the book B. the most wonderful part in the book. C. the major part in the book D. the scientific part of the book.
　　39. The last two sentences of the first paragraph mean that . A. a reading speed too slow for a difficult book is just right for a non-serious one. B. a reading speed too slow for a non-serious book may be too fast for a difficult one. C. A reading speed too fast for difficult material is just right for a non-serious book is also too slow for a difficult one. D. A reading speed too slow for a non-serious book is also too slow for a difficult one.
　　40. Which of the following can be the title of the passage？
　　A. Reading and listening B. Difference between highly-educated and poorly educated C. Practice reading skill D. Difference in the speed and efficiency of reading