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Test Seven
1
Lacking a cure for AIDS, society must offer education, not only by public pronouncement but in classrooms. Those with AIDS or those at high risk of AIDS suffer prejudice, they are feared by some people who find living itself unsafe, while others conduct themselves with a“bravado(冒险心理)” that could be fatal. AIDS has afflicted a society already short on humanism, open handedness and optimism. Attempts to strike it out with the offending microbe are not abetted(教唆) by preexisting social ills. Such concerns impelled me to offer the first university level undergraduate AIDS course, with its two important aims:
To address the fact that AIDS is caused by a virus, not by moral failure or societal collapse. The proper response to AIDS is compassion coupled with an understanding of the disease itself. We wanted to foster(help the growth of) the idea of a humane society.
To describe how AIDS tests the institutions upon which our society rests.The economy, the political system, science, the legal Establishment, the media and our moral ethicalphilosophical attitudes must respond to the disease. Those responses, whispered, or shrieked, easily accepted or highly controversial, must be put in order if the nation is to manage AIDS. Scholars have suggested that how a society deals with the threat of AIDS describes the extent to which that society has the right to call itself civilized. AIDS, then, is woven into the tapestry(挂毯) of modern society; in the course of explaining that tapestry, a teacher realizes that AIDS may bring about changes of historic proportions. Democracy obliges its educational system to prepare students to become informed citizens, to join their voices to the public debate inspired by AIDS. Who shall direct just what resources of manpower and money to the problem of AIDS? Even more basic, who shall formulate a national policy on AIDS? The educational challenge, then, is to enlighten(启发) the individual and the societal, or public, responses to AIDS.
1. What is the passage mainly about?
A. Why education must be offered about AIDS.
B. How to achieve the aims of AIDS courses.
C. Risks associeted with AIDS.
D. Social responses to AIDS.
2. Why did the author offer the AIDS course?
A. He wanted to teach people about a cure for AIDS.
B. People need to be taught how to avoid those with AIDS.
C. He wanted to teach the students that AIDS resulted from moral failure.
D. People take improper attitudes towards AIDS and those with or at high risk of AIDS.
3. The word “afflict” in the third sentence of the first paragraph most probably means “____”.
A. benefit B. cause suffering to
C. teach D. draw attention from
4. What does the author think is the correct response to AIDS?
A. Fear and contempt.
B. Optimism and bravado.
C. Understanding and compassion.
D. Resentment and avoidance.
5. Which of the following can best explain “AIDS tests the institutions upon which our society rests” according to the passage?
A. AIDS is a sign of moral failure and social collapse.
B. AIDS indicates that our social systems have been very inefficient.
C. The responses of a society to the threat of AIDS determines whether and to what extent the society can be called civilized.
D. The spreading of the fatal disease suggests that the nation’s resources have been wrongly used.
2
The idea of a fish being able to generate electricity strong enough to light lamp bulbs—or even to run a small electricmotor—is almost unbelievable, but several kinds of fish are able to do this. Even more strangely, this curious powerhas been acquired in different ways by fish belonging to very different families.
Perhaps the best known are the electric rays, or torpedoes(电鳐), of which several kinds live in warm seas. They possess on each side of the head, behind the eyes, a large organ consisting of a number of hexagonal shaped cells rather like a honeycomb. The cells are filled with a jellylike substance, and contain a series of flat electric plates. One side, the negative side, of each plate, is supplied with very fine nerves, connected with a main nerve coming from a special part of the brain. Current passes from the upper, positive side of the organ downwards to the negative, lower side. Generally it is necessary to touch the fish in two places, completing the circuit, in order to receive a shock.
The strength of this shock depends on the size of the fish, but newly born ones only about 5 centimetres across can be made to light the bulb of a pocket flashlight for a few moments, while a fully grown torpedo gives a shock capable of knocking a man down, and, if suitable wires are connected, will operate a small electric motor for several minutes.
Another famous example is the electric eel. This fish gives an even more powerful shock. The system is different from that of the torpedo in that the electric plates run longitudinally(纵向) and are supplied with nerves from the spinal(脊骨) cord. Consequently, the current passes along the fish from head to tail. The electric organs of these fish are really altered muscles and like all muscles are apt (likely) to tire, so they are not able to produce electricity for very long.
The power of producing electricity may serve these fish both for defence and attack.
6. It can be seen from the passage that ____.
A. the capacity to generate electricity is the distinctive characteristic of the fish
B. the current travels in an upward direction from the positive side to negative side in torpedo’s electric cells
C. some fish can produce enough electricity to drive a number of electricmotors
D. the torpedo’s electric cells have a shape with six sides
7. Usually you will not get a shock by touching the electric ray in one place only because ____.
A. the current in one place is not strong enough to give a shock
B. the fish’s electric cells are filled with jellylike substance
C. to complete the circuit, you have to touch the fish in two places
D. a torpedo’s electric cells contain more than one electric plates
8. The main idea of the third paragraph is that ____.
A. a mature torpedo is capable of producing enough electricity to knock down a man
B. the mass of the fish decides the intensity of electric power it generates
C. the strength of shock given by a young electric ray can only light the bulb of a pocket flashlight
D. to make full use of the energy produced by electric fish, suitable wires should be available
9. The reason why the electric eel is able to give more powerful shock is that ____.
A. the working system of the electric plates in the eel is the most effective
B. the working system of the electric plates in the eel is far inferior to those in the torpedo
C. compared with those in the torpedo, the working system of electric plates in the eel is more direct and efficient
D. compared with other electric fish, the eel possesses much more electric plates
10.The ideal title for this passage is ____.
A. The Eel B. Torpedo
C. Electric Fish D. Electric Power
3
In some urban centers, workaholism is so common that people do not consider it unusual: They accept the lifestyle as normal. Government workers in Washington,D.C., for example, frequently work sixty to seventy hours a week. They don’t do this because they have to; they do it because they want to.
Workaholism can be a serious problem. Because true workaholics would rather work than do anything else, they probably don’t know how to relax; that is, they might not enjoy movies, sports, or other types of entertainment. Most of all, they hate to sit and do nothing. The lives of workaholics are usually stressful, and this tension and worry can cause health problems such as heart attacks or stomach ulcers. In addition typical workaholics don’t pay much attention to their families. They spend little time with their children, and their marriages may end in divorce.
Is workaholism always dangerous? Perhaps not. There are, certainly, peoplewho work well under stress. Some studies show that many workaholics have great energy and interest in life. Their work is so pleasurable that they are actually very happy. For most workaholics, work and entertainment are the same thing. Their jobs provide them with a challenge; this keeps them busy and creative.
Why do workaholics enjoy their jobs so much? There are several advantages to work. Of course, it provides people with paychecks, and this is important. But it offers more than financial security. It provides people with selfconfidence; they have a feeling of satisfaction when they’ve produced a challenging piece of work and are able to say, “I made that.” Psychologists claim that work gives people an identity; through participation in work, they get a sense of self-satisfaction and individualism. In addition, most jobs provide people with a socially acceptable way to meet others. Perhaps some people are compulsive about their work, but their addiction seems to be a safe—even an advantageous—one.
11.A workaholic is a person who ____.
A. has to work at least 8 to 9 hours a day
B. volunteers to work for long hours
C. is addicted to work
D. has the work with more responsibility than others
12.One of the reasons that some people are not willing to quit even in their eighties and nineties is that ____.
A. they are in the need of financial security
B. they would rather work than be disturbed by domestic discord
C. they long for a sense of identity and being accomplished
D. they may have health problems from sheer boredom
13.The main idea of the passage is that ____.
A. workaholics are usually successful people, but their lives are in a mess
B. workaholism can lead to serious problems but it can also create a joyful life
C. people who indulge in their work may enjoy movies, sports and other kinds of entertainment
D. those who work even under difficult conditions may be very happy
14.It can be inferred from the passage that ____.
A. in the eyes of all the common people workaholics are peculiar
B.to workaholics work is the sole source of happiness
C. a piece of challenging work may provide the workaholics a sense of satisfaction
D. workaholics are as addicted to their job as other people are to drugs or alcohol
15.The author’s attitude towards workaholism is ____.
A. favorable B. critical
C. worried D. neutral
4
Peopel who do sleep research tell us that a person is a sort of “information processor.” We have two ways to use the information we get each day.
The first process is used when we are awake. It takes place in the left side of the brain. It is this process that makes us do the things we have to do. It lets us put aside those things that are not a real part of our day’s work.
The second process happens in the right side of the brain. This process takes all those bits of information we did not use in the day. It turns them to dreams at night. “This process is our regular nightshift work,” says physiologist Rosalind Cartwright from the University of Illinois. “At night we put together the bits and pieces of our day, so that we are ready to face the next day.”
We have several dreams each night of our lives. About ten minutes after we fall asleep, we begin to go through four stages of sleep. Our sleep gets deeper and deeper. And it gets harder for us to wake up. At the end of the fourth and deepest stage, the process changes. We begin to come back up again through the same stages. The coming back up is called “rousal” time. It lasts about ten to twenty minutes. We do not wake in this stage. Instead, we go through a stage of vivid dreams.
In this stage we do not toss or turn or even snore. The brain temperature and the blood flow get much higher. The body goes as limp as a rag doll. And the large muscles in the arms, legs, and trunk go stiff. The eyeballs begin to move back and forth very quickly, even though the eyes are closed. This is called the stage of Rapid Eye Movement or the REM stage.
We go into the REM stage about six times a night. That’s once every hour and a half or so.This hour and a half pattern is part of many things in our lives. Lots of body functions happen every hour and a half. Things like stomach contractions(收缩) and hormone secretions(分泌).
Why do we dream? Research tells us that dreams can help us with our problems. When we have big problems in the day, we may spend more time in REM sleep at night, because dreams can bring answers to problems.
16.Sleep research reveals ____.
A. people do odd things in the first stage of sleep
B. the left side of our brain is responsible for the work that is necessary to deal with during the day
C. the mysteries of dreams have just been brought to light
D. the function of the right side of our brain is to classify the information we fail to handle in the daytime
17.By calling the coming back up“rousal time”, the author means in this stage ____.
A. people are likely to sleepwalk
B. people become mentally active
C. people often wake up
D. people might do odd things
18.During one’s REM stage ____.
A. no other body functions but stomach contractions and hormone secretion take place
B. his body move restlessly
C. his body as well as his mind can get good rest
D. he might walk into a graphic dreamland
19.The example of hormone secretion is given in the passage to illustrate____.
A. hormone secretes in our REM stageB. functions such as hormone secretions are of great importance to us
C. the hour and a half pattern of REM sleep take place with many other body functions
D. many body functions have great effect on our sleep
20.The author writes this passage mainly to ____.
A. interpret the modes of various dreams
B. delve further the proces of information we get each day
C. discuss the causes that provoke dreams
D. bring to light some of the facts about dreams
答案部分
1
短文大意
本文讨论的是为什么要开设关于艾滋病课程的问题。由于缺乏治愈艾滋病的办法，社会就必须加强教育，不仅在公共场合而且要在课堂上。人们对艾滋病病人或有艾滋病风险的人有偏见，而某些人又太随便，这些都已对社会造成了危害。这就是作者为什么要开设艾滋病课程的原因。
1. 答案A。
【参考译文】 本文主要是关于什么的?
【试题分析】 本题要求掌握文章的大意。
【详细解答】
解答此题与确定中心思想的方法基本一致。读完全文以后，再将每小段的首尾句都放在一起看，基本上可确定文章的话题与要旨。
若每段首尾句主干放在一起，我们可以发现文章的要点构成的框架：
Society must offer education(第一段首句)… Such concerns impelled me to offer the first universitylevel undergraduate AIDS course, with its two basic aims(第一段尾句): To address the fact that AIDS is caused by a virus, …(第二段首句)。…We wanted to foster the idea of a humane society(第二段尾句)。To describe how AIDS tests the institutions upon which our society rests(第二小段首句)。…Theeducational challenge, then, is to enlighten the individual and the societal, or public, responses to AIDS.
这样，便很快明白原文主要说明“我”为什么开设AIDS课程，也用来说明第一句society must offer education about AIDS。
2. 答案D。
【参考译文】 作者为什么要开设艾滋病课程?
【试题分析】 本题要求了解作者的态度和意图。
【详细解答】 作者在文中第一小段说了他开设AIDS course的原因。
此小段最后一句是：
Such concerns impelled me to offer the first universitylevel undergraduate AIDS course. 那么such concerns指什么呢?在该句之前有三句，讲了三点，其中第一点就是人们对AIDS病人或有AIDS病的风险的人有偏见，有些人又太随便(with a bravado)；这一点导致第二点：AIDS has afflicted a society。第三点是：并非早已存在的社会丑恶现象／病态教唆人们试图用有害的微生物去消灭艾滋病。暗示意思是说：人们这样做是有其深层的思想原因的。
基于以上分析，结合文中第二、三小段，可以知道这一题答案是选项D，而不是选项A、B或C。
3. 答案B。
【参考译文】 第一段第三句中的“afflict”这个词最可能是“cause suffering to”的意思。
【试题分析】本题考查考生根据上下文猜测词义的能力。
【详细解答】 afflict所在的句子及我们的常识告诉我们，其意义决不可能是benefit或teach。afflict所在句子的前一句提到人们害怕艾滋病人，而冒险心理可能是致命的。这令我们联想：AIDS危险，对社会有伤害。所以选项B最有可能是afflict的意义解释。
4. 答案C。
【参考译文】 作者认为对艾滋病的正确反应是什么?
【试题分析】 本题要求了解作者的态度和意图。
【详细解答】 这一题答案在第二小段第二句中。选项C是唯一的正确选项，而A、B、D都是与原文内容背道而驰的。
5. 答案C。
【参考译文】 根据本文，下面哪一句能够最好地解释“AIDS tests the institutions upon which our society rests”?
【试题分析】 本题要求理解个别句子的意义，也理解上下文之间的逻辑关系。
【详细解答】 题干中引号部分出现在原文第三小段的第一句中。读者得先明白此句的意思：为了描述AIDS如何考验我们的社会赖以存在的基本机构。文中后面的部分则说明这一句。此小段第四句(Scholars have suggested that how a society deals with the threat of AIDS describes the extent to which that society has the right to call it civilized.)意为：学者们提出，一个社会如何应付艾滋病的威胁表明该社会在何种程度上有权称为文明社会。有常识的读者都知道，一个社会如何应付某一问题取决于社会的基本部分或机构如何应付它。因而应将这一句与第三小段第二、三句联系起来。可以看出这些社会机构对AIDS的反应与how a society deals with the threats of AIDS是一回事。
那么，可以说第三小段第四句解释了题干中引号内的内容。
比较A、B、C、D四个选项，可知只有选项C与该句意思相同。C为答案。
2
短文大意
本文讨论的是有关能发电的特殊鱼类及其具体发电过程。人们不会相信鱼能够发电点亮灯泡，甚至可以发动小型发动机，但有几种鱼能够做这一切，最为人们所知的电鱼，还有电鳗，它们发电是为了保卫自己和攻击。
6. 答案D。
【参考译文】 从本文可以看出，电鳐的发电细胞的形状是六边形。
【试题分析】 本题要求了解文章主旨的事实和细节。
【详细解答】 这一题要求我们在对全文整体理解后，并一一对照文中细节，才能做出选择。A认为“产生电的能力是鱼类的一种有别于其他生物的特性”。事实上鱼类中只少数几种特殊的鱼有产生电的能力，并非所有的鱼类。因此A项是不正确的。
B认为“电流经过电鳐细胞的正极向上到达负极。”而文中第二段很清楚写有电流从上方的正极向下流到下方的负极，B项是错的。
C认为“有些鱼能产生足以开动几台电动机的电量。”而文中对于鱼类所产生的电量的描述最惊人的也只能发动一台小电机。因此B项是不正确的。
D项认为“电鳐的发电细胞的形状是六边形。”在文中第二段曾提到电鳐的发电细胞像蜂窝，由日常知识，我们知道蜂窝是六边形的，所以D是正确的。
7. 答案C。
【参考译文】 通常你触摸电鳐不会在一个地方感受到电击只是因为你得触摸鱼的两边从而使电路循环完成才会感受到电击。
【试题分析】 本题要求了解文章的细节。
【详细解答】 这一题主要是对细节部分的考查。第二段中的最后一句话详细地写道，“通常需触摸鱼的两边从而使电路循环完成，这样才会感受到电击。”从这里的completing the circuit(完成循环)，我们不难看出C项是正确的。
8. 答案B。
【参考译文】 第三段的中心思想是鱼的质量决定了它发电的强度。
【试题分析】 本题要求理解有关材料的中心思想。
【详细解答】 这一题也要求我们运用整体理解概括出中心并注意中心与细节的区别。我们可以看到第三段只有一句话，而主句是说“电击的强度取决于鱼的大小”，随后分别以具体事实对比了大小不同的鱼的发电量。所以B项“鱼的质量决定了它发电的强度”。反映了第三段的中心。其它三项都只描述一些细节。
9. 答案C。
【参考译文】 电鳗能够发出更强大的电击的原因是因为与电鳐相比，电鳗的发电棱鳞的工作系统更直接和更有效。
【试题分析】 本题要求了解主要事实的细节。
【详细解答】 在第四段中，作者详细地说明了电鳗的发电系统，电鳗的发电组织是纵向的，由脊骨的神经供电，因而电流从头至尾流动。而电鳐的发电器官是蜂窝状且分布于头部两侧，可以看出电鳗由于其脊骨神经供电，电流可直接由头传至尾，较顺畅，可推断出电鳗的发电系统较之电鳐更直接也更有效一些，所以应选C项。
10.答案C。
【参考译文】 本文的理想题目是发电的鱼。
【试题分析】 本题要求理解文章的中心思想。
【详细解答】 文章的题目其实也就是对全文中心的归纳，整篇文章都在叙述有关能发电的特殊鱼类及其具体发电过程。A项“电鳗”当然不正确，全文说明的鱼类不只鳗鱼一类，且重点也不是鳗鱼而是其发电系统。B项“电鳐也同样不正确，C项“发电的鱼”这显然与全文主题相切，D项“电力”这与全文中题相切，D项“电力”这与全文中心差距太大，所以应选C项。
3
短文大意
本文讨论的是工作狂问题。工作狂可能是个严重的问题，因为真正的工作狂只愿工作，除此以外什么也不干。他们不知如何放松休息，但工作狂并非总是危险的，并且有很多好处。它给人带来金钱，给予人自信和满足感、成就感。
11.答案C。
【参考译文】 工作狂就是沉溺于工作的人。
【试题分析】 本题要求了文章主旨的事实。
【详细解答】 通过上下文对workaholic的描述，我们可看到，他们不知如何松驰自己，不愿享受娱乐活动，甚至不愿干坐着而宁愿工作，这种人我们通常称之为工作狂，由此我们可推出，C项“沉溺于工作的人”是正确的，如果不熟悉addict一词也可通过排除法来做，A项“每天须工作至少8—9小时的人”。工作时间长的人不一定是工作狂，也可能是由于压力或不得以才工作，所以不准确。B项“自愿长时间工作的人”。自愿长时间工作的人不一定出于对工作的狂热，也可能迫于经济压力，所以B项也不准确，D项“工作的责任性比别人更大的人”。干责任性大的工作的人也不一定是狂热地爱工作，视工作为享受的工作狂，所以D是不准确的，应选C项。
12.答案C。
【参考译文】 有些人到了八、九十岁都不愿放弃工作的原因之一是他们渴望一种成功和个人成就感。
【试题分析】 本题要求理解文章主旨的细节。
【详细解答】 文中提到了工作狂热爱工作的理由，除了工资，工作还能给予人自信和满足感，所以八、九十岁的老人仍然工作当然不再为了工资或健康问题，很明显，答案是C。他们渴望一种成功和个人成就感。
13.答案B。
【参考译文】 本文的中心思想是工作狂可能会引起严重问题，但也能够创造快乐的生活。
【试题分析】 本题要求掌握文章的中心思想。
【详细解答】 这一题主要考察了事实与主题的区别，有的选项是原文中提到的事实但并不一定是全文的主题。A项“工作狂通常是成功的人但他们的生活却一团糟”和D项“那些即使在困难条件下工作的人可能也很快乐”，都是文中提到的事实但非主题，全文围绕的主题是工作狂热可能会产生严重的问题但不总是危险的，他们也有益处，所以B项才是正确的。而C项“那些沉溺于工作的人们享受电影，体育和其它方式的娱乐”而文中提到工作狂不喜欢娱乐，因此这一项是错误的。
14.答案D。
【参考译文】 从本文可以推断，工作狂就像人们沉溺于毒品和酒一样沉溺于工作。
【试题分析】 本题要求对文章进行一定的判断和推理。
【详细解答】 这一题我们要注意infer(推断)一词，也就是说有些选项符合全文的意思，但它们是全文直接描写出来的，而非读者通过思考推理出来的，这样的选项也不符合题意。A项“在普通人眼中工作狂很特殊”。这与原文相反，原文提到人们并认为工作狂的生活方式是不正常的。
B项“对工作狂来说，工作是快乐的唯一来源”，第三段提到对工作狂来说工作就是娱乐，因此无须推断。
C项“有挑战性的工作可能给工作狂带来满足感”。这是原文中明确提到，而非推断出的，所以C是不正确的。
D项“工作狂就像人们沉溺于毒品和酒一样沉溺于工作”我们可看到工作狂对工作的热爱如同上了瘾一样，可推出这一项是正确的。
15.答案A。
【参考译文】 作者对工作狂的态度是赞同的。
【试题分析】 本题要求领会作者的观点和态度。
【详细解答】 这篇文章前半部分列举了工作狂带来的问题，但其后笔锋一转，认为工作狂并非总是危险的，并描写其诸多好处，篇尾还提到这种沉溺看起来是安全的，甚至是有益的，由此我们可推出，作者对工作狂的态度是赞同的。很明显应选A项。
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短文大意
本文讨论的是对睡眠的研究。人们对睡眠研究后得出结论，人是一种信息加工者，运用信息的过程有两个。第一个过程发生在我们清醒时在左脑，第二个过程发生在右脑，在夜里。每天晚上都会做梦，入睡以后会经历睡眠的四个阶段。
16.答案B。
【参考译文】 睡眠研究表明我们的左脑负责处理白天应做的工作。
【试题分析】 本题要求了解文章主旨的细节。
【详细解答】 这一题很明显是对细节的考查，开篇第一句就告诉我们人们对睡眠研究后得出的一种结论，即人是一种信息加工者，运用信息的过程有：第一发生在我们清醒时，我们的左脑指挥我们做该做的事情，进入睡眠后第二个过程便在右脑开始了，使白天未用到的信息成为我们的梦。在仔细阅读这些细节后，我们就可开始判断选项了。
A项认为“人们在睡眠的第一阶段做奇怪的事”，而全文基本上未提及人们在睡眠第一阶段时行为怪异，人们在睡眠的第一阶段只是睡着了且不及后三阶段睡得沉，所以A项不正确。
B项认为“左脑负责处理白天应做的工作”这显然与原文相符。
C项认为“梦之谜已被揭开了”，而原文中未曾提及揭开梦之谜的事，而现实中梦之谜也确未被揭开，所以C项不正确。
D项认为“右脑的职能是将白天未能处理的信息分类”，这显然与原文不符。
17.答案B。
【参考译文】 作者把重新回来叫做“‘rousal’ time”，意思是人们的思想开始变得活跃起来。
【试题分析】 本题要求理解有关细节的上下文的逻辑关系。【详细解答】 这一题也要求我们注意联系上下文并注意细节，在提到“rousal” time，文中写道：它持续十到二十分钟，在这一阶段我们不会醒来而进入一个多梦的阶段，rousal是生造出的词，从rouse演变而来，有become active的意思，由此我们不难判断出B项“人们的思想开始变得活跃”是正确的。
18.答案D。
【参考译文】 在人的REM阶段，他会进入一个生动的梦境。
【试题分析】 本题要求了解主旨的事实和细节。
【详细解答】 看REM stage我们应知道这是一个关键词，从五段到七段基本都与REM stage有关，这就要求我们对这几段能充分理解，文中提到第四个阶段人们进入一个多梦的阶段，并描述这一段的一些特征，并称这一阶段为REM阶段，可见在REM阶段人们会做一些生物的梦，所以应选D项“他会进入一个生动的梦境”。而A项认为“除了胃部收缩和分泌荷尔蒙外身体的其他职能停止作用”，文中提到胃部收缩和分泌荷尔蒙是作为身体职能两个例子，并未提到其他职能就不发生作用，所以A是不正确的。B项认为人的身体在REM阶段不断运动，而文中提到手臂、腿和胸部的肌肉此时是僵硬的，所以B是不正确的，而C项认为身体和大脑都得到良好的休息，这显然是错误的。
19.答案C。
【参考译文】 本文列举荷尔蒙分泌的例子是为了说明许多身体功能每90分钟作用一次的方式。
【试题分析】 本题要求了解文章主旨的细节。
【详细解答】 文中举例说明许多身体职能每90分钟作用一次时列举了分泌荷尔蒙和胃部收缩，并写到 生活中许多事情属于90分钟方式，因此这一题应选C。
20.答案D。
【参考译文】 作者写本文的目的是揭示关于梦的一些事实。
【试题分析】 本题要求掌握文章的主旨。
【详细解答】 对这种判断主要意思的题要在整体理解的基础上找出中心并运用排除法，排除那些提到却未深入分析的干扰项。
A项认为“解释了各种梦的模式”，文中并未就梦的模式作过描述，因此是不正确的。
B项“深入研究我们每天所获得的信息的过程”，文中提到对信息加工的两个过程，且未继续对这两个过程进行分析，所以B也不正确。
C项认为“讨论了产生梦的原因”，而全文都在讲述梦的发生及其特征，用的也是一种描述性语气，不曾探究原因，在最后一段中有“为什么我们做梦”的语句，但也未就产生梦的原因作出分析，所以C项是不正确的。
D项认为“讲明了一些梦的事实”这的确是全文围绕的中心，所以应选D项。
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