Question

【題目】 Most of us spend a third of our lives sleeping. Scientists have been studying the brain to learn what happens while we sleep. Scientists tell us that there are four stages(階段)of sleep. During each stage our brain behaves differently, and so does our body. Each stage is marked by changes in the pattern of brain waves, which can be recorded by machines.

In the first stage, we drift off to sleep. Our muscles(肌肉)begin to relax. Our heartbeat and breathing slow down. Body temperature and blood pressure(壓力)begin to drop. Stage—two sleep is a time of small, fast brain waves. Our eyes move quickly from side to side as if watching a movie. This is known as rapid eye movement, or REM sleep. During REM sleep, dreaming takes place. In stage three the brain wave becomes slower again.

Within about 45 minutes after falling sleep, we progress into the fourth stage – deep sleep. As this happens, our brain sends out slower but larger brain waves. This is the most restful kind of sleep, but it is also the time when sleepers are most likely to change positions or sleepwalk. After deep sleep we return to stage two. As the hours pass, we repeat the sleep cycle four or five times. Then we wake up.

【1】How many stages of sleep do we repeat several times during a night?

A.Two.B.Three.C.Four.D.Five.

【2】When does a person most likely change his positions?

A.When first falling asleep.B.During stage three.

C.During REM sleep.D.During deep sleep.

【3】Which of the following statements is TRUE?

A.We can dream in all the stages of sleep, especially during REM sleep.

B.It is impossible to record the pattern of our brain waves with machines.

C.Our body, like our brain, behaves differently during each stage of sleep.

D.It takes about 45 minutes to complete the sleep cycle after we fall asleep.

Answer 1

【答案】

【1】B

【2】D

【3】C

【解析】

我們生命中有三分之一的時(shí)間在睡覺，科學(xué)家想了解我們睡覺的時(shí)候大腦是怎么運(yùn)作的。人的睡眠可以分為四個(gè)階段，本文分別介紹了這四個(gè)階段。

【1】細(xì)節(jié)理解題。根據(jù)“After deep sleep we return to stage two. As the hours pass, we repeat the sleep cycle four or five times. ”可知，當(dāng)我們進(jìn)入深睡眠以后，我們會(huì)從第二階段開始重復(fù)。因此我們睡覺重復(fù)的是2、3、4階段。故選B。

【2】細(xì)節(jié)理解題。根據(jù)“This is the most restful kind of sleep, but it is also the time when sleepers are most likely to change positions or sleepwalk. ”可知this指代第四階段深睡眠，在這個(gè)階段最可能變換姿勢(shì)。故選D。

【3】細(xì)節(jié)理解題。根據(jù)“During REM sleep, dreaming takes place.”可知我們通常在REM睡眠的時(shí)候做夢(mèng)，因此A選項(xiàng)是錯(cuò)誤的；根據(jù)“ Each stage is marked by changes in the pattern of brain waves, which can be recorded by machines.”可知科學(xué)家用機(jī)器記錄每個(gè)階段的腦電波，因此B選項(xiàng)是錯(cuò)誤的；根據(jù)“ During each stage our brain behaves differently, and so does our body. ”可知每個(gè)階段我們得大腦和身體的行為是不同的，因此C選項(xiàng)是正確的；根據(jù)“Within about 45 minutes after falling sleep, we progress into the fourth stage – deep sleep.”可知睡著以后得45分鐘我們會(huì)進(jìn)入睡眠的第四階段，并非45分鐘完成一個(gè)循環(huán)，因此D選項(xiàng)是錯(cuò)誤的。故選C。