Question

How would you like to sleep with one half your brain asleep and the other half awake? Dolphins sleep this way. Recently, scientists at Indiana State University have discovered that ducks sleep this way too. They found that ducks sleep half awake so they can rest and watch for danger at the same time.

After putting their ducks in a row and videotaping them, some researchers found ducks on the end of each row spent more time asleep with one eye open, apparently looking for predators.

“The more the ducks felt threatened, the more they slept with one eye open,” said lead author Niels C. Rattenborg, a graduate student at Indiana State University, Terre Haute. “The unique aspect is not that they do it, but that they control it. When they sleep at the edge of a group, they tend to realize greater danger, so they spend more time sleeping with one half of their brain.” Ducks with one eye open were still awake enough to detect predators, said the authors of the study, which appears today in the journal Nature.

The researchers studied four groups of four ducks held in plastic boxes, which were arranged in a row. Ducks on the end were found to sleep with one eye open 31.8 per cent of the time, compared to 12.4 percent of the time for ducks in the central position.

Also, ducks in the central position did not open one eye more than the others, while ducks on each end kept the eye facing away from the group open 86.2 per cent of the time. Brain wave readings of the ducks showed that the half of the brain receiving signals from the closed eye indicated that half of the brain was sleeping. Signals from the half of the brain receiving signals from the open eye showed a state between fully awake and asleep.

1.The under lined word “predator” is most likely to mean       .

A. an animal that is likely to be friends with ducks

B. a human being who looks after and feeds ducks

C. a scientist who does research work on animals

D. an animal that hunts, kills and eats other animals

2.Ducks at the end of each row sleep with one eye open because       .

A. they are looking for food

B. they are watching out for danger

C. they want to enjoy the scenery

D. they are unique in their sleeping habit

3.Which of the following is true according to the passage?

A. Ducks with one eye open at the edge can still enjoy a certain degree of sleep.

B. Ducks with less sense of duty usually choose to stay in the center of a row.

C. Ducks on the northern end of a row would keep their eye facing the south open.

D. A video tape recorder was the only electronic device used in the experiment. 

 

Answer 1

【答案】

 

1.D

2.B

3.A

【解析】

試題分析：文章介紹了海豚和鴨子在休息的時候有一半大腦是清醒的，一半是休息的，在休息時有一只眼睛也是不斷睜開的，研究者們也做了一系列的實(shí)驗(yàn)來證明他們是這么做的，并且了解了這么做的原因，主要是為了防止可能會出現(xiàn)的危險(xiǎn)。

1. D細(xì)節(jié)理解題。They found that ducks sleep half awake so they can rest and watch for danger at the same time. 研究員們發(fā)現(xiàn)，鴨子在休息時一半是清醒的，因此他們能夠同時注意危險(xiǎn)；The more the ducks felt threatened, the more they slept with one eye open鴨子越感覺危險(xiǎn)，他們睡覺時一只眼睛睜得越多。由此可知他們睡覺睜一只眼睛是為了尋找可能出現(xiàn)的危險(xiǎn)。故答案應(yīng)為D。

2.B細(xì)節(jié)理解題。some researchers found ducks on the end of each row spent more time asleep with one eye open, apparently looking for predators. 句意為：一些研究員發(fā)現(xiàn)，在每隊(duì)邊上的鴨子花費(fèi)更多的時間睜著眼睛睡覺，很明顯他是是警惕危險(xiǎn)；When they sleep at the edge of a group, they tend to realize greater danger, so they spend more time sleeping with one half of their brain.當(dāng)他們在邊的時候，他們往往會意識到更大的危險(xiǎn)，因此他們花費(fèi)更多的時間保持他們大腦的清醒。故答案應(yīng)為B。

3.A細(xì)節(jié)判斷題。文章第一自然段說明鴨子和海豚睡覺時大腦一半是清醒的一半是休息的，因此在邊上的鴨子也有一定程度的休息是正解的。Ducks with less sense of duty usually choose to stay in the center of a row.沒有責(zé)任感的鴨子通常選擇在一排的中間，文章里沒有說明鴨子是選地方休息的；Ducks on the northern end of a row would keep their eye facing the south open文中沒有提到哪個方向的鴨子面朝向哪個方向；A video tape recorder was the only electronic device used in the experiment.文中提到了這個設(shè)備，但沒說明是唯一的，故答案A是正確的。

【考點(diǎn)】考查科普環(huán)保類文章的閱讀理解。