英语四级阅读理解专练带答案

英语四级阅读理解专练带答案

英语四级阅读理解专练原文

Sleep is very ancient. In the electroencephalographic(脑电图的)sense we share it with all theprimates(灵长类动物)and almost all the other mammals and birds: it may extend back as far asthe reptiles(爬行动物).

There is some evidence that the two types of sleep, dreaming and dreamless, depend on thelife style. of the animal, and that predators(食肉动物)are statistically much more likely to dreamthan prey, which are inturn much more likely to experience dreamless sleep. In dream sleep,the animal is powerfully immobilized(使固定不动)and remarkably unresponsive to externalstimuli. Dreamless sleep is much shallower, and we haveall witnessed cats or dogs cocking theirears to a sound when apparently fast asleep. The fact that deep dream sleep is rare amongprey today seems clearly to be a product of natural selection, and it makes sensethat today,when sleep is highly evolved, the stupid animals are less frequently immobilized by deepsleepthan the smart ones. But why should they sleep deeply at all? Why should a state of suchdeep immobilization ever have evolved?

Perhaps one useful hint about the original function of sleep is to be found in the fact thatdolphins and whales and aquatic mammals in general seem to sleep very little. There is, byand large, no place to hide in the ocean. Could it be that, rather than increasing an animalsvulnerability,

Ray Meddis of London University has suggested this to be the case. It isconceivable that animals that are too stupid to be quite on their own initiative are, duringperiods of high risk, immobilized by the implacable arm of sleep. The point seems particularlyclear for the young of predatory animals. This is an interesting notion and probably at leastpartly true. 英语四级阅读理解专练题目

1.Which of the following might be the best title for this passage?

A.Evolution of Sleep.

B.Two Types of Sleep.

C.The Original Function of Sleep.

D.Animals and Sleep.

2.Predators are ___________.

A.able to prey even when they are in deep dream sleep

B.more likely to experience dream sleep

C.incapable of preying when immobilized by dreamless sleep

D.good at preying on stupid animals

3.The example of dogs and cats in the second paragraph is intended to _

A. explain which animals are mammals

B. show the differences between mammals

C. illustrate how shallow dreamless sleep is

D. reveal how smart they are

pare with dreamless sleep, deep dream sleep is _______.

A. not the result of natural selection

B. less likely to appear to primates

C. more protective to the animals

D. at a higher stage of evolution

5.According to some scientists research findings, dolphins seldom sleep because __.

A.of their stupidity

B.of their vulnerability

C.there are possible dangers in the ocean

D.aquatic mammals do not need sleep

英语四级阅读理解专练答案

1.[A] *三段虽然讨论的内容各有侧重，但是都谈到了睡眠在各种动物中的差异以及发展的历史，具体用词如下:第1段第1句中的ancient,最后一句中的extend back;第2段最后一句中的evolved;第3段第1句中的original function。A比较准确地归纳了*大意。B只是概括了第2段的内容;C只提及第3段的论述

内容;D似乎涵盖了三段内容,但是过于宽泛,不够具体。

2.[B] 根据第2段第1句第4个分句可知应选B。A的内容与该段第2句相悖;C中dreamless sleep应为dreamsleep。D的内容文中没有涉及。

3.[C] 这个例子是为了证明无梦睡眠比较浅，即第2第3句的前半句，所以选C比较合适。所有例子都是为之前或之后的话提供例证，因此,作者使用例子