[外语类试卷]大学英语四级模拟试卷18及答案与解析.doc

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1、大学英语四级模拟试卷 18及答案与解析 一、 Part I Writing (30 minutes) 1 For this part, you are allowed thirty minutes to write an eye-witness account of a rescue after a traffic accident. You should write no more than 120 words according to the outline given below in Chinese 假设你在 “五一 ”节乘车回家的路上目击一起救助车祸伤者的情况，就此为当地报社写一份报

2、道。报道须包括以下几点： 1. 车祸发生的时间及地点； 2. 你所见到的车祸救援情况 (警方、民众和医护人员等 )； 3. 评述人与人之间的这种相互关爱。 An Eye-Witness Account of a Rescue after a Traffic Accident 二、 Part II Reading Comprehension (Skimming and Scanning) (15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer

3、 the questions attached to the passage. For questions 1-7, mark： Y (for YES) if the statement agrees with the information given in the passage; N (for NO) if the statement contradicts the information given in the passage; NG (for NOT GIVEN) if the information is not given in the passage. 2 Life on O

4、ther Planets In 1961, scientists set up a gigantic, sensitive apparatus to collect radio waves from the far roaches of space, hoping to discover in them some mathematical pattern indicating that the waves were sent out by other intelligent beings. The first at tempt failed; but someday the experimen

5、t may succeed. But is there intelligent life? Life that has reached the stage of being able to send radio waves out-into space in a planned pattern? Our own planet may have been in existence for five billion years and may have had life on it for two billion, but it is only in the last fifty years th

6、at intelligent life capable of sending radio waves into space has lived on earth. From this it might seem that even if there were no technical problems involved, the chance of receiving signals from any particular earth-type planet would be extremely small. This does not mean that intelligent life a

7、t our level does not exist somewhere. There is such an unimaginable number of stars that, even with only a small chance, it seems certain that there are millions of intelligent life forms scattered through space. The only trouble is, none may be within hailing distance of us. Perhaps none ever will

8、be; perhaps the huge distances that separate us from our fellow inhabitants of this universe will forever remain too great to be conquered. And yet it is conceivable that someday we may come across one of them or, frighteningly, one of them may come across us. What would they be bike, these extrater

9、restrial creatures? Surely, it would seem, there is no way of telling. Here on earth alone, life has developed in many directions, taking on forms that could scarcely be invented by the wildest imagination if they were not already known to exist. Who would dream that a mouse could fly if he had neve

10、r seen a bat? Who would predict blind lizards living in caves, or worms living in the intestines of other creatures? Consider the giraffe, the humming-bird, the redwood tree, the Venus flytrap, and see whether you can imagine any limit to various forms of life. Then how can anyone predict anything a

11、t all a bout extraterrestrial beings? Ah, but all these variations and modifications that exist on earth are in some ways only superficial. In the chemists test tube, all amazing differences in life forms vanish when we consider the basic similarity of those life forms, which is neither exciting nor

12、 amazing. Whatever appearance earth creatures may have, they are all made up of the same kinds of complex molecules; with minor variations, they all make use of the same chemical machinery. For all its wonderful differences, life on earth is merely an imaginative variation on a single chemical struc

13、ture. Life on any earthlike planet may prove to be similar. As we understand life, it consists of molecules large enough and complex enough to meet the infinitely flexible requirements of living tissue. The molecules must be stable enough to retain their structure under some conditions, and unstable

14、 enough to change kaleidoscopically under other conditions. In living things on earth, the most important molecules of this type are the proteins, and as far as we know, nothing will substitute for them. Furthermore, the changes these proteins undergo in the process of living can only take place aga

15、inst a watery back ground. Life began in the oceans, and even the various forms of land life are still from 50 to 80 percent water. The chemical structure, then, upon which life is based, here and possibly on all earth-type planets, is protein-in water. If we are ever to meet up with creatures from

16、an earth-type planet, we may not be able to predict their appearance, but we can predict that, whatever their shape, they will very likely be protein-in-water. But what about life on planets that are not like the earth? What about planets so close to their sun that their surfaces are hot enough to m

17、elt lead? What about planets so far from their sun that water is eternally frozen? Are such worlds barren for ever? It would seem so, certainly, if all life were only protein-in-water. But can we be sure that life cannot be based on other structures? Suppose, for instance, that in a world on which l

18、iquid water cannot exist because of frigid temperatures, there was a substance that could take the place of water. Actually, there is such a substance, and it is called ammonia. Everyone is familiar with the bottled ammonia that looks like water but has a strong smell. This is actually only ammonia

19、dissolved in water; ammonia itself is a gas at ordinary temperatures. Under conditions on earth it does not become a liquid until it is cooled to thirty degrees below zero Fahrenheit and does not freeze until a temperature of one hundred degrees below zero is reached. The cold worlds of our own sola

20、r system, such as Jupiter and Saturn, have thick atmospheres that are mainly hydrogen and helium but contain a strong mixture of ammonia. There is good reason to think that any large cold planet would have an atmosphere of this sort. It is conceivable, then, that such planets, even with all water fr

21、ozen into ice, might have oceans of liquid ammonia in which life might develop in a completely alien manner. Actually, ammonia strongly resembles water in the way it dissolves substances, so the structure of protein-in-ammonia is fascinatingly possible under conditions where the temperature is too c

22、old for protein-in-water. What about the hot planets close to a sun? Certainly there would be no water; if any existed at the beginning, it would have boiled away eons ago. Perhaps life would develop in substances that are liquid at high temperatures. Sulfur is liquid between temperatures of 235 and

23、 800 degrees Fahrenheit. Could there be sulfur- based life? It there is, it could scarcely be based on ordinary protein, which would be highly unstable at such elevated temperatures. There are molecules called silicones which could conceivably be built into complex structures able to survive high te

24、mperatures. Silicones have been developed in the laboratory here on earth. Solid silicones serve, among other things, as a kind of artificial rubber, and liquid silicones have been used as hydraulic fluids. Can we picture life forms on hot planets with rubbery tissues and hydraulic fluid bloodstream

25、s, living in puddles of liquid sulfur? We have already undergone a radical broadening of thought in beginning to accept the fact that we may not be the only world of living creatures in the universenot even, perhaps, the only living intelligences. Will we someday undergo another broadening of though

26、t and accept ourselves as an example of only one of the possible chemical structures of life? If so, is it possible that we will find ourselves studying, with fascination, the absolutely alien life chemistry of the silicone Hots and the ammonia Colds, with ourselves the only examples of the protein-

27、in-water InBetweens? I cant help hoping flat when we venture into space we will find things beyond even our wildest speculations. And why not? In science, as in every thing human, it is the chance of the unexpected that gives excitement to efforts. 2 Even intelligent life on earth couldnt send radio

28、 waves half a century ago. So it would be impossible for any intelligent beings to exist on any other planet at that time. （ A） Y （ B） N （ C） NG 3 The author believes that other life forms are so far away from our planet that we could never meet them. （ A） Y （ B） N （ C） NG 4 The author says that sil

29、icones might replace protein on hot planets because silicones may remain stable under very high temperatures. （ A） Y （ B） N （ C） NG 5 The author mentioned flying mice, blind lizards and worms in order to show that many strange things occur in the world. （ A） Y （ B） N （ C） NG 6 Modern theories of the

30、 development of stars suggest that almost every star has some sort of family of planets. （ A） Y （ B） N （ C） NG 7 Scientists collect radio waves from space in hopes that they might receive planned messages sent by intelligent life on an other world. （ A） Y （ B） N （ C） NG 8 Jupiter and Saturn are com

31、worlds of the solar system. （ A） Y （ B） N （ C） NG 9 The chemical structure of a creature from an earth-type planet will very likely be _. 10 The author believes that life on other planets can take on forms _ because even life on our own planet assumes such strange and various forms. 11 In terms of c

32、hemical structure, the passage mainly discusses three substances. They are _. Section A Directions: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the q

33、uestions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A, B, C and D, and decide which is the best answer. （ A） He me all the food. （ B） lie cleaned the refrigerator. （ C） He worked day and night. （ D） lie had a big lunch

34、. （ A） Hes playing sports. （ B） Hes watching sports games. （ C） Hes driving. （ D） Hes fighting. （ A） She didnt feel well. （ B） She went dancing earlier. （ C） She came down to go dancing. （ D） She got mad at the woman. （ A） $5. （ B） $5.60 （ C） $4.40 （ D） $6.60 （ A） In a shipping company office. （ B）

35、In Professor Bensons office. （ C） In a publishers office. （ D） In a university store. （ A） They will have to take a different bus. （ B） The trip is too dangerous. （ C） They will have to wait. （ D） There is a problem with the bus. （ A） A secretary. （ B） A novelist. （ C） A newspaperman. （ D） A busines

36、sman. （ A） In New York. （ B） In Boston. （ C） In Michigan. （ D） In Washington. （ A） Relaxing at the seashore. （ B） Visiting her parents. （ C） Sailing on a boat. （ D） Preparing for a race. （ A） She was invited only for the weekend. （ B） The weather was too hot. （ C） She had an appointment. （ D） She ha

37、d schoolwork to do. （ A） She had to go home. （ B） She was too tired to continue. （ C） She had to finish her schoolwork. （ D） She was thirsty. （ A） The man wants to obtain an international drivers license that he can use both in the U.S, and in his country. （ B） The man wants to take a drivers test t

38、o get an Arizona drivers license. （ C） The man wants to know whether he can use his international drivers license in Arizona. （ D） The man wants to fill out an application for an Arizona drivers license. （ A） Show his student ID and pay ten dollars. （ B） Use his international drivers license. （ C） T

39、ake a drivers test and apply for a limited license. （ D） Show proof of temporary residence. （ A） Less than one year. （ B） Four years. （ C） Five years. （ D） Ten years. （ A） Fill out an application. （ B） Go back to the university to get his ID. （ C） Go to see his friend. （ D） Take a written exam and a

40、n eye exam. Section B Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C an

41、d D. （ A） It is a good place to land at by aeroplane. （ B） It is a good place to fly over. （ C） It is a good place to travel to by land. （ D） It is a good place to live at. （ A） Because there planes fly higher than at the equator. （ B） Because there the eyes can reach about 4,000 metres. （ C） Becaus

42、e there planes are clear of bad weather. （ D） Because there planes fly more quickly than at the equator. （ A） In warm air. （ B） In cold air （ C） When it reaches the polar region. （ D） Only when the clouds are down low. （ A） At low latitudes. （ B） At mid-latitudes. （ C） At high latitudes. （ D） At hig

43、h altitudes. （ A） Latitude. （ B） Longitude. （ C） Sea. （ D） Mountain. （ A） Brazil. （ B） Argentina. （ C） Chile. （ D） Ecuador. （ A） Nine out of ten. （ B） One third. （ C） Elven out of thirty. （ D） One fourth. （ A） The cat can reach their terminal speed. （ B） The cat does not change its final speed. （ C）

44、 His legs spread out and muscles absorb more force of impact. （ D） He will slow down and reduce the damage. （ A） Cats can change their position while falling. （ B） The force of impact with the ground over four legs is spread. （ C） Cats can land on their feet after falling. （ D） Their muscles can abs

45、orb more of the force of impact. （ A） Nine out of ten cats have a better chance of survival. （ B） What is the significance of the seventh floor? （ C） Whats the cats terminal speed? （ D） Most cats can survive when falling. Section C Directions: In this section, you will hear a passage three times. Wh

46、en the passage is read for the first time, you should listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the blanks numbered from 36 to 43 with the exact words you have just heard. For blanks numbered from 44 to 46 you are required to fil

47、l in the missing information. For these blanks, you can either use the exact words you have just heard or write down the 37 Cats are 【 B1】 _ of habit. They like to go to sleep about the same time every day and for a certain 【 B2】 _ of time. They seem to have a 【 B3】 _ clock inside them that tells th

48、em when to sleep. Cats 【 B4】 _ their regular sleep with 【 B5】 _ catnaps. Some experts feel that human could also 【 B6】 _ from this habit. Catnaps help to build up 【 B7】 _ in the body. They are also a good way to overcome 【 B8】 _. Since cats have moods similar to those of humans, some experts believe

49、 that 【 B9】 _. 【 B10】 _. The naps would usually last from fifteen to thirty minutes. Winston Churchill took catnaps. So did Presidents Harry Truman, John F. Kennedy, and Lyndon B. Johnson. 【 B11】_. Perhaps more people could learn from eats and take naps to feel better and live longer! 37 【 B1】 38 【 B2】 39 【 B3】 40 【 B4】 41 【 B5】 42 【 B6】 43 【 B7】 44 【 B8】 45 【 B9】 46 【 B10】 47 【 B11】 Section A Directions: In this section, there is a short