大学英语四级-86及答案解析.doc

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1、大学英语四级-86 及答案解析(总分：100.00，做题时间：90 分钟)一、Reading Comprehensio(总题数：4，分数：100.00)The Internet is an international collection of computer networks that all understand a standard system of addresses and commands, connected together through backbone (中枢) systems. It was started in 1969, when the U.S. Depart

2、ment of Defense 1 a nationwide network to connect a handful of universities and contractors (订约人). The 2 idea was to increase computing capacity that could be shared by users in many locations and to find out what it would take for computer networks to 3 a nuclear war or other disasters by providing

3、 multiple paths between users. People on the ARPNET (as this nationwide network was originally called) quickly discovered that they could exchange messages and conduct electronic “conferences“ with distant colleagues for 4 that had nothing to do with the military industrial complex. If somebody else

4、 had something interesting 5 on their computer, it was a simple matter to obtain a copy (assuming the owner did not protect it). Over the years, additional networks joined which added 6 to more and more computers. The first international connections, to Norway and England, were added in 1973. Today

5、thousands of networks and millions of computers are connected to the Internet. It is growing so quickly that nobody can say 7 how many users “on the Net“. The Internet is the largest repository (知识库) of information which can provide very large network resources. The network resources can be 8 into n

6、etwork facilities resources and network information resources. The network facilities resources provide us the ability of 9 computation and communication. The network information resources provides us all kinds of information 10 , such as science, education, business, history, law, art, and entertai

7、nment, etc. A. access B. original C. divided D. survive E. debates F. established G. purposes H. genuine I. exactly J. remote K. possibility L. stored M. totally N. services O. maintain（分数：25.00）Once they decided to have children, MiShel and Carl Meissner tackled the next big issue: Should they try

8、to have a girl? It was no small matter. MiShel“s brother had become blind from a hereditary condition in his early 20s, and the Meissners had learned that the condition is a 11 passed from mothers to sons. If they had a boy, he would have a 50 per cent chance of having the condition. A girl would be

9、 12 . The British couple“s inquiries about gender selection led them in 1999 to Virginia, US where a new sperm (精子)-separation technique, called MicroSoft, was under 13 . When MiShel became pregnant, she gave birth to a daughter. They will try to have a second daughter using the technique later this

10、 year. The technique separates sperm into two groupsthose that carry the X-chromosome (producing a female baby) and those that carry the Y-chromosome (producing a male baby). The technology was developed in 1990s, but last month“s opening of a laboratory in California 14 the company“s first expansio

11、n. “We believe the number of people who want this technology is greater than those who have 15 to it,“ said Keith L. Blauer, the company“s clinical director. This is not only a 16 effective way to select a child“s gender. It also brings a host of ethical (伦理的) and practical considerationsespecially

12、for the majority of families who use the technique for 17 reasons. The clinic offers sex selection for two purposes to help couples avoid passing on a gender4inked 18 disease and to allow those who already have a child to “balance“ their family by having a baby of the opposite sex. The technology is

13、 still 19 . However, Blauer says the company has an impressive success rate: 91 per cent of the women who become pregnant after sorting for a girl are successful, while 76 per cent who sort for a boy and get pregnant are successful. The technique separates sperm based on the fact that the X-chromoso

14、me is larger than the Y-chromosome. A machine is used to 20 the size differences and sort the sperm accordingly. The result is then checked using another type of DNA analysis to ensure that it contains mostly X-or Y-bearing sperm. The desired sample is then used for artificial insemination (授精) or t

15、est tube fertilization. A. genetic B. overlapped C. marked D. unaffected E. perpetually F. investigation G. access H. feat I. disorder J. gropes K. experimental L. seemingly M. elicit N. nonmedical O. distinguish（分数：25.00）The greenhouse effect causes trouble by raising the temperature of the planet.

16、 The 21 rise is not very much, but the Earth“s ecosystem is very weak, and small changes can have large effects. It has been believed that this 22 of one degree will happen by the year 2025. This could probably 23 the North American corn belt, which produces much of the world“s grain, 24 to much hig

17、her food prices, and even less food for the Third World than they already have. However, it would also mean that some countries which are further north would be able to 25 crops they had never been able to before, although there is less land as you move north from the corn belt. The other serious wo

18、rry is that rising sea levels from the melting of the polar ice could 26 flood many countries. A rise in sea levels of one meter, which many experts are 27 by the year 2100 (and some as soon as 2030), would flood 15 percent of Egypt, and 12 percent of Bangladesh. The Maldives in the Indian Ocean wou

19、ld almost 28 disappear. Most of the countries which would suffer most from a rise in sea levels are the poor 29 states, so the islands in the Caribbean, South Pacific, Mediterranean and Indian Ocean have formed the Alliance of Small Island States, AOSIS, so they have a 30 voice in international poli

20、tics and can make the richer developed world listen to their problems. A. severely B. damage C. island D. critical E. grow F. mainland G. louder H. predicting I. rise J. completely K. geometry L. actual M. extending N. leading O. develop（分数：25.00）Many people wonder why some men want to live on the m

21、oon. It is 31 not the kind of place where most men would choose to live. But man has always moved to new areas. Some scientists hope that continued work will be done on the moon. Many experiments will be done there more 32 . Some large 33 are very easy to do in a place without air. Matter can be hea

22、ted to very high temperatures without 34 change when it is in such a place Air, dust; and clouds cannot 35 man“s view of space from the moon. The very high or very low temperatures and low gravity on the moon will be used for many experiments. One very important use of the moon will be to 36 spacesh

23、ip. Man might be able to learn much about his own body by living on the moon. He would be living in a habitat that he made for himself. Man would be in control of the 37 of life in which he lives. 38 could be removed from the air in this community. Gravity is the one thing that would not be under ma

24、n“s control. Some scientists believe the low gravity of the moon would be 39 for man. The heart would not have to work so hard. The body would need less energy to move than it does on the earth. However, the human body might change during long stays on the moon Much exercise would probably be needed

25、 to keep the body in good 40 . A. community B. condition C. launch D. insight E. chemical F. mysterious G. experilnents H. probably I. healthful J. easily K. extend L. render M. promptly N. block O. bacteria（分数：25.00）大学英语四级-86 答案解析(总分：100.00，做题时间：90 分钟)一、Reading Comprehensio(总题数：4，分数：100.00)The Inte

26、rnet is an international collection of computer networks that all understand a standard system of addresses and commands, connected together through backbone (中枢) systems. It was started in 1969, when the U.S. Department of Defense 1 a nationwide network to connect a handful of universities and cont

27、ractors (订约人). The 2 idea was to increase computing capacity that could be shared by users in many locations and to find out what it would take for computer networks to 3 a nuclear war or other disasters by providing multiple paths between users. People on the ARPNET (as this nationwide network was

28、originally called) quickly discovered that they could exchange messages and conduct electronic “conferences“ with distant colleagues for 4 that had nothing to do with the military industrial complex. If somebody else had something interesting 5 on their computer, it was a simple matter to obtain a c

29、opy (assuming the owner did not protect it). Over the years, additional networks joined which added 6 to more and more computers. The first international connections, to Norway and England, were added in 1973. Today thousands of networks and millions of computers are connected to the Internet. It is

30、 growing so quickly that nobody can say 7 how many users “on the Net“. The Internet is the largest repository (知识库) of information which can provide very large network resources. The network resources can be 8 into network facilities resources and network information resources. The network facilitie

31、s resources provide us the ability of 9 computation and communication. The network information resources provides us all kinds of information 10 , such as science, education, business, history, law, art, and entertainment, etc. A. access B. original C. divided D. survive E. debates F. established G.

32、 purposes H. genuine I. exactly J. remote K. possibility L. stored M. totally N. services O. maintain（分数：25.00）解析：F解析 此处需要及物动词的过去式，作谓语。该句的主语是 the U.S. Department of Defense，宾语是 network，由此可以推断出答案为 established(建立)。解析：B解析 此处需填形容词，修饰 idea。上一句提到因特网始于 1969 年，接着该句描述了当初建立网络的目的，因此可知 original 正确。解析：D解析 此处需填入及

33、物动词，且为原形。本句仍为当初建立网络的目的，而根据其宾语 a nuclear war or other disasters，可选出 survive，意为“幸存，幸免于”。解析：G解析 此处需名词。根据其后的 that 定语从句知道描述的正是最初建立网络的“目的”，因此应该很容易就确定 purposes 最为合适。解析：L解析 此处需动词过去分词，构成 have sth. done 结构。根据下文的 obtain copy，可知something interesting 是在计算机里面的，由此可知 stored 正确。解析：A解析 此处需填名词。根据上文的 additional network

34、s joined，可以推测网络使越来越多的计算机连接在一起，因此 access 符合这一要求。解析：I解析 此处需要副词。根据 so quickly 和 how many 可得出答案为 exactly(准确地)。解析：C解析 此处需填动词的过去分词，构成被动语态，且能与 into 搭配。根据上下文句意，即可推测该词为“分开”之义，所以答案 divided。divide into 意为“分成”。解析：J解析 此处需形容词，修饰 computation and communication。前文第一段已提到人们可以通过网络与远处的同事互换信息及进行电子“会议”，所以该形容词应与距离有关，因此 rem

35、ote 最合适，意思是“远程的”。解析：N解析 此处需填名词。由下文 such as 后的列举的科学、教育、商业等，可知 services 正确。information services 意为“信息服务”。Once they decided to have children, MiShel and Carl Meissner tackled the next big issue: Should they try to have a girl? It was no small matter. MiShel“s brother had become blind from a hereditary

36、condition in his early 20s, and the Meissners had learned that the condition is a 11 passed from mothers to sons. If they had a boy, he would have a 50 per cent chance of having the condition. A girl would be 12 . The British couple“s inquiries about gender selection led them in 1999 to Virginia, US

37、 where a new sperm (精子)-separation technique, called MicroSoft, was under 13 . When MiShel became pregnant, she gave birth to a daughter. They will try to have a second daughter using the technique later this year. The technique separates sperm into two groupsthose that carry the X-chromosome (produ

38、cing a female baby) and those that carry the Y-chromosome (producing a male baby). The technology was developed in 1990s, but last month“s opening of a laboratory in California 14 the company“s first expansion. “We believe the number of people who want this technology is greater than those who have

39、15 to it,“ said Keith L. Blauer, the company“s clinical director. This is not only a 16 effective way to select a child“s gender. It also brings a host of ethical (伦理的) and practical considerationsespecially for the majority of families who use the technique for 17 reasons. The clinic offers sex sel

40、ection for two purposes to help couples avoid passing on a gender4inked 18 disease and to allow those who already have a child to “balance“ their family by having a baby of the opposite sex. The technology is still 19 . However, Blauer says the company has an impressive success rate: 91 per cent of

41、the women who become pregnant after sorting for a girl are successful, while 76 per cent who sort for a boy and get pregnant are successful. The technique separates sperm based on the fact that the X-chromosome is larger than the Y-chromosome. A machine is used to 20 the size differences and sort th

42、e sperm accordingly. The result is then checked using another type of DNA analysis to ensure that it contains mostly X-or Y-bearing sperm. The desired sample is then used for artificial insemination (授精) or test tube fertilization. A. genetic B. overlapped C. marked D. unaffected E. perpetually F. i

43、nvestigation G. access H. feat I. disorder J. gropes K. experimental L. seemingly M. elicit N. nonmedical O. distinguish（分数：25.00）解析：I解析 此处应为单数名词。根据该句中的 blind 一词可以知道句中提到的 condition 其实是一种“疾病”，“不正常的情况”，显然 disorder 为本题答案。解析：D解析 此处应为动词的分词形式或形容词，表示女孩的状态。根据该段对这种遗传病的描述可以知道生女孩可以避免遗传到这种病，因此，空白处的单词应该表明“没事”、“不

44、受影响”等，因此本题答案为 unaffected。解析：F解析 此处应为名词，可与 under 搭配，表明精子分离技术的现状。在名词词库中，investigation 是最适合本题的词，under investigation 表明这种技术正处于发展研究当中。解析：C解析 此处应为动词过去式。本句的内容表明实验室的启动“标志”着该公司的第一次扩张，因此答案为 marked。解析：G解析 此处应为名词，可与 have 和 to 搭配成 have n. to sth. 的词组。根据搭配的要求在名词词库中寻找，可以发现 access 为本题答案。have access to.意为“有权/能够使用”。解

45、析：L解析 此处应为副词，形容这种新技术有效使用的程度或范围。根据上文描述的个案，可以知道这种技术“看起来”很有用，而在副词词库中，seemingly 具有与此相同的意思，因此本题答案为seemingly。解析：N解析 此处应为修饰成分，可为名词、形容词或动词的分词。从破折号前的 ethical and practical considerations 可以知道空白处提到的原因可能有悖伦理标准，即并非处于医学上的需要而使用了这种技术，由此可见，nonmedical 是本题答案。解析：A解析 此处应为修饰成分，可为名词、形容词或动词的分词。从本文首段提到的个案和本句提到的 gender-link

46、ed 可以推断空白处的单词应表明“遗传性”疾病，因此 genetic 为本题答案。解析：K解析 此处应为形容词或动词的分词，作句子的表语。从本句中的 still 和下句 However 引出的内容可以知道，这种技术虽然成功率很高，但研究仍没有定论，因此本题答案应为 experimental，表明技术仍处于“试验阶段”。在形容词词库中，nonmedical 也可用于形容 technology，但很明显，本文提到的技术就是与医学有关的，所以不选。解析：O解析 空白处应为原形动词。该句中的 size differences 和 sort 都表明机器起到“筛选”、“分辨”的作用，因此本题答案为 dis

47、tinguish。The greenhouse effect causes trouble by raising the temperature of the planet. The 21 rise is not very much, but the Earth“s ecosystem is very weak, and small changes can have large effects. It has been believed that this 22 of one degree will happen by the year 2025. This could probably 23

48、 the North American corn belt, which produces much of the world“s grain, 24 to much higher food prices, and even less food for the Third World than they already have. However, it would also mean that some countries which are further north would be able to 25 crops they had never been able to before,

49、 although there is less land as you move north from the corn belt. The other serious worry is that rising sea levels from the melting of the polar ice could 26 flood many countries. A rise in sea levels of one meter, which many experts are 27 by the year 2100 (and some as soon as 2030), would flood 15 percent of Egypt, and 12 percent of Bangladesh. The Maldives in the Indian Ocean would almost 28 disappear. Most of the countries which would suffer most from a rise in sea levels are the poor 29 states, so the islands in the Caribbean, South Pacific, M