Question

Do you find that late at night, your homework done, you aren't tired enough to sleep? In fact, you could get out of bed and go for a run, or play a quick game of basketball? It's not a good feeling because, although you don't feel sleepy, you certainly will in the morning．

It's probably not coffee or tea or other stimulants （刺激物） that are the problem．Indeed, it may not be a problem at all, according to some researchers, just the way the teenage body works．But not all schools seem to realize this．

    It seems that some American schools are getting the message and giving teenagers more time to sleep in the morning．They've found that starting after 8 am makes students more likely to turn up on time to school, do better work, and generally feel happier．

But in most American schools after school activities like sports and bus routes are given as reasons for a morning start time between 7 am and 8 am．

All this, the US National Sleep Foundation （美国国家睡眠协会） says, has serious consequences for teenagers．It means they don't get the 8．5 to 9．5 hours of sleep a night they need．In fact, some teens get just 7 hours or less under the covers．

Researchers have come to the conclusion over the last 10 years that teens cannot easily fall asleep until about 11 pm and need to sleep until about 8 the next morning．

    Mary Carskadon of Brown University was in charge of a study of teen saliva （口水）．Her team measured the amount of sleep-producing hormone （荷尔蒙） in the saliva．

She found teens have a higher hormone level late at night than either adults or young children．It also remains high the morning after．Why this is the case is not yet clear to scientists．But experts say they do know that the consequences to teenagers sleep deprivation （剥夺） are more serious than classrooms full of sleepy kids．

Falling asleep at roll call （点名） is just the beginning of the problem．In her book Snooze … or Lose Helen Emsellem says that sleep-deprived teens get sick more easily, are prone （易于） to headaches and get poorer grades．

1．According to the article, what contributes to many teenagers' late sleeping habits?

       A．Coffee and tea．                                 B．their habits．

  C．Activities before sleep．                     D．Biological clock．

2．According to researchers, starting schools later in the morning is likely to ______．

  A．improve teenagers' performance in studies 

  B．make teenagers get sick more easily

  C．help teenagers get on with each other better

 D．lead teenagers to go to bed later

3．Which group has the highest sleep-producing hormone level in their saliva late at night?

A．Young children．                           B．Teenagers．

C．The middle-aged．                         D．Old people．

4．Which of the following is FALSE?

  A．Early morning starts are to blame for teen sleep deprivation．

B．Many American teenagers have trouble getting enough sleep．

  C．Many American schools argue that after school activities help teenagers sleep．

  D．The book Snooze … or Lose stresses the importance of good sleep for teenagers．

5．Which of the following can be the best title of the passage?

  A．Live Longer with better sleep            B．More Sleep needed

  C．Sleepy? Spend less on activities          D．Unhealthy habits ruin good sleep

Answer 1

DABCB