Question

    Why is that many teenagers have energy to play computer games until late at night， but can't find the energy to get out of bed in time for school？ According to a new report， today's teenagers are getting so little sleep but their health is in danger．

This raises serious questions about whether being short of sleep is influencing children's ability to pay attention at school． Research has shown that losing even just half an hour's sleep at night can have deep influences on how children perform the next day．

So why aren't teenagers getting enough sleep？Some experts suggest that televisions， computers and mobile phones in children's bedrooms may cause problems．Instead of reading a book at bedtime，children are playing computer games，surfing the web，sending messages， or watching television．As these new pre-sleep activities have become more common，more traditional ones such as reading have become less，Dr．Luci Wiggs，a researcher at Oxford

University's Section of Child and Adolescent Psychiatry said，“One of the problems with these pre-sleep activities is that they do not have clear start and end times which leads to being short of sleep．”

Research has shown that teenagers have different sleep patterns from adults．Human bodies produce melatonin（褪黑激素）to help fall asleep． Most adults start to produce melatonin at

about 10 pm，while teenagers only begin to produce it three hours later．It is possible that this  delay in melatonin production is caused by the behaviors of teenagers such as playing with phones late at night．

Problems about sleep- who needs how much and when -are usually connected to students' achievements． But modern brain researchers say it is time that more schools wake up to both biological and social facts and make a better timetable for their teenager students．

1.What can we learn from Paragraph 2？

A.It's very common for teenagers to have less sleep．

B.It doesn't matter if children sleep half an hour less．

C.Being short of sleep has influence on children．

D.A good night sleep at weekends helps children study well．

2.According to Dr．Luci Wiggs，．

A.too many pre-sleep activities take up teenagers' sleeping time．

B.playing computer games before bedtimes does harm to health．

C.fewer and fewer children read books at bedtime today．

D.teenagers shouldn't watch TV before they go to sleep．

3.What does the underlined word 'delay' mean？

A.Rushing． B.Changing． C.Putting off． D.Cutting off．

4.What can we infer from Paragraphs 4 and 5？

A.Schools need to offer more biology classes．

B.Teenagers may be kept awake by themselves．

C.Melatonin influences teenagers' achievements．

D.It's necessary for schools to start classes later．

5.Which can be the best title for this passage？

A.Wake Up Sleeping Teenagers

B.Let Sleeping Teenagers Lie

C.Keep Away From Electronic Products

D.How to Sleep

Answer

1.C

2.A

3.C

4.C

5.C

【解析】

短文大意：短文关注的是青少年的睡眠健康，通过研究发现太多的睡前活动占用了青少年的睡眠时间，而睡眠不足会影响他们在学校的注意力和成绩，建议远离电子产品保证充足的睡眠时间。

1.

细节理解题。根据“Research has shown that losing even just half an hour's sleep at night can have deep influences on how children perform the next day研究表明，即使晚上少睡半个小时，也会对孩子第二天的表现产生深远影响”，可知睡眠不足对孩子有影响，故选C。

2.

细节理解题。根据“So why aren't teenagers getting enough sleep? Some experts suggest that televisions， computers and mobile phones in children's bedrooms may cause problems那么为什么青少年睡眠不足呢?一些专家认为，孩子卧室里的电视、电脑和手机可能会造成问题”，可知太多的睡前活动占用了青少年的睡眠时间，too many pre-sleep activities take up teenagers' sleeping time符合题意，故选A。

3.

词义理解题。根据“Most adults start to produce melatonin at about 10 pm，while teenagers only begin to produce it three hours later大多数成年人在晚上10点左右开始产生褪黑激素，而青少年在3小时后才开始产生”，可知青少年产生褪黑激素的时间延后了，put off符合句意，故选C。

4.

细节理解题。A. 学校需要提供更多的生物课；B. 青少年可能会自己保持清醒；C. 褪黑素影响青少年的成就；D. 学校推迟上课是必要的。根据“Problems about sleep- who needs how much and when -are usually connected to students' achievements关于睡眠的问题——谁需要多长时间睡多少觉——通常与学生的成绩有关”，可知谁需要多长时间睡多少觉会影响到学生的成就，故选C。

5.

标题归纳题。根据短文对学生睡眠不足的分析，结合“it is time that more schools wake up to both biological and social facts and make a better timetable for their teenager students现在是时候让更多的学校意识到生物学和社会事实，并为他们的青少年学生制定更好的时间表了”，可知本文劝诫青少年远离电子产品，Keep Away From Electronic Products（远离电子产品）符合文意，故选C。