Question

Ever feel like you’ve been hit on the head after a bad night’s sleep? According to scientists, the thought isn’t as unbelievable as it seems.

A study found going without sleep for just one night causes changes in the brain similar to those that occur after a blow to the head. The researchers said the healthy young men examined in the study showed a sudden increase in the same chemicals which indicate brain damage. Professor Christian Benedict, of Uppsala University, Sweden, explained that the chemicals NSE and S-100B are biomarkers for brain damage, such as concussion(脑震荡). He said, "What we found was their levels in the blood rose in the group that went without sleep for a night. This was not to the extent that would happen after a head injury, for instance, but it was still significant. During sleep, the brain cleans poisonous substances off itself."

Benedict also said previous studies which linked a lack of sleep with increased risk of Alzheimer’s, Parkinson’s and multiple sclerosis could applaud his study. The rise of the chemicals in the blood after sleep loss may suggest not getting enough sleep contributes to a loss of brain tissue, he explained. Benedict, whose study is published in the journal Sleep, added, "In conclusion, the findings of our experiment indicate a good night’s sleep may be critical to maintaining brain health."

A third of the UK population suffer from sleep-related problems, while the average person now sleeps for only seven hours a night, compared with almost nine a few decades ago. Many scientists believe irregular sleeping patterns lead to illnesses ranging from aches and pains to heart disease, while less than eight hours’ sleep a night can lower the IQ the next day.

1.If you don’t sleep for a night, what will happen?

A.NSE and S-100B will increase.

B.The brain damage will be likea head injury.

C.You will suffer from concussion.

D.The brain will get rid of poisonous substances.

2.What do we know about previous studies?

A.They found reasons for brain disorders.

B.Their findings were published inSleep.

C.They were supported by Benedict’s study.

D.They focused on brain health.

3.What can we infer from the last paragraph?

A.UK people have the worst sleep.

B.Man’s intelligence is affected by sleep in a way.

C.People were smarter in the past.

D.A lack of sleep causes all brain-related problems.

4.What’s the main idea of the passage?

A.Eight hours’ sleep is important.

B.Regular sleeping patterns improve health.

C.Sleep loss is close to a blow to the head.

D.Human brains work during sleep.

Answer

1.A

2.C

3.B

4.C

【解析】

试题分析：本文是一篇科普类说明文。科学家们发现，睡眠不足对大脑造成的损伤接近头部重击，不足八小时的睡眠甚至会降低第二天的智商。

1. 细节理解题。根据文章第二段的"What we found was their levels in the blood rose in the group that went without sleep for a night"中的their指的就是前面提到的"the chemicals NSE and S-100B"，由此可知，一晚上不睡觉的话，血液中的化学物质NSE和S-100B就会增加。故选A。

2. 推理判断题。根据第三段中的"Benedict also said previous studies which linked a lack of sleep with increased risk of Alzheimer’s, Parkinson’s and multiple sclerosis could applaud his study"可知，Benedict说以前的研究表明睡眠不足与阿尔茨海默氏症、帕金森和多发性硬化症的风险增加有关，这可以为他的研究提供支持。接着Benedict解释了为什么先前的研究会赞成他的研究，即"The rise of the chemicals in the blood after sleep loss may suggest not getting enough sleep contributes to a loss of brain tissue"（睡眠不足后血液中化学物质的增加可能暗示睡眠不足导致大脑组织丢失）。综上可推知，Benedict的研究支持了先前的研究。故选C。

3. 推理判断题。根据文章最后一段中的"less than eight hours’ sleep a night can lower the IQ the next day"可知，睡眠少于八小时的人第二天智商会降低，这暗示人的智力在某种程度上受睡眠的影响。故B项正确。

4. 主旨要义题。根据文章内容，尤其是第一段及第二段的首句可知，本文主要围绕“睡眠不足对大脑造成的损伤接近于头部遭重击”这一主题展开。故C项最能概括文章的大意，而其他选项都比较片面。故选C。

【学法指导】

抓住文章主线和关键词语，归纳文章中心

要注意不是所有的段落都有主题句，有时主题句暗含在句中。阅读这样的文章，就需要自己根据文章的细节来分析，概括出段落的主题，从而推导出文章的主旨。分析的方法是：先弄清该段落主要讲了哪几方面的内容，这些内容在逻辑上有什么联系，然后加以归纳形成主题。5. 主旨要义题。根据文章内容，尤其是第一段及第二段的首句可知，本文主要围绕“睡眠不足对大脑造成的损伤接近于头部遭重击”这一主题展开。故C项最能概括文章的大意，而其他选项都比较片面。故选C。

考点：考查科普类说明文