Question

    Sleepiness and boredom lead to yawning (打哈欠), so it has long been believed that the action makes us feel more awake by stretching the muscles surrounding the lungs, or by bringing more oxygen to the blood and the brain. Yet in tests, breathing air with high levels of carbon dioxide or even pure oxygen made no difference to the frequency of yawns.

Another theory, proposed by the French physician Olivier, is that yawning improves the circulation of the fluid (液体) that surrounds the brain. As a result, we can focus better on a task. This might explain why athletes often yawn naturally before they compete.

Recently, though, a new explanation has appeared: Yawning is a way to cool the brain. Experiments led by Gordon Gallup at the University at Albany showed that people yawned far less when their head was cooled by a cold pack compared with holding a heated pack to their forehead The temperature of the brain rises when we are tired, so it is possible that yawning is a way to protect the brain from overheating due to tiredness.

But a strange thing is that when we see another person yawn, we catch it too. In other words, yawning is contagious.

How can we make sense of these different types of yawning? It’s possible that contagious yawning is something different, and might have a social purpose. Steven Palek and his colleagues at the University at Albany say that contagious yawning may be linked to our ability to understand what others want to do. If you are good at reading others’ facial expressions you are more likely to “catch” a yawn. Therefore, lonely people tend to be less affected by yawing, according to research by Atsushi Senju, now at Birkbeck, University of London.

So the simple act of yawning tursout to be surprisingly complex Has this research made you yawn yet?

1.Based on the theory of Olivier, yawning ________.

A.is caused by lack of sleep

B.contributes to concentration

C.is a way to bring more oxygen to the blood

D.increases the circulation of the fluid in lungs

2.The underlined word “contagious” in Paragraph 4 is closest in meaning to _________.

A.Infectious B.Influential

C. Attractive D.Comfortable

3.How is the passage mainly developed?

A.By making comparisons.

B.By listing different figures.

C.By providing explanations.

D.By telling personal experiences.

Answer

1.B

2.A

3.C

【解析】

本文是一篇说明文，从不同的角度解释了打哈欠的现象。

1.细节理解题。根据第二段中的“Another theory, proposed by the French physician Olivier, is that yawning improves the circulation of the fluid (液体) that surrounds the brain. As a result, we can focus better on a task.”可知，法国医生奥利维尔提出的理论是，打哈欠可以改善大脑周围的血液循环，因此，我们可以更好地专注于一项任务，也就是说打哈欠有助于集中注意力，故B项正确。

2.词义猜测题。根据画线词前的“when we see another person yawn, we catch it too”可知，当我们看到另一个人打哈欠时，我们也会跟着打哈欠，这说明打哈欠会传染，由此可知画线词词义为“传染的”.A. Infectious 传染的；B. Influential有影响力的；C. Attractive吸引人的；D.Comfortable 舒服的。故A项正确。

3.推理判断题。通读全文，特别是根据第一段中的“it has long been believed that the action makes us feel more awake by stretching the muscles surrounding the lungs, or by bringing more oxygen to the blood and the brain.”，第二段中的“Another theory, proposed by the French physician Olivier, is that yawning improves the circulation of the fluid (液体) that surrounds the brain. As a result, we can focus better on a task.”，第三段中的“Yawning is a way to cool the brain.”及第四段中的“In other words, yawning iscontagious.”可知，本文分别从四个角度解释了打哈欠的现象，即：打哈欠让我们保持清醒、打哈欠让我们更专注、打哈欠可以给大脑降温、打哈欠会传染，因此，文章是通过提供解释来行文的，故C项正确。