阅读理解。
     Do You Go To Sleep In Class?
     The "Acronym", our student newspaper, reports that most students go to sleep at 1: 30 a. m. Even if
 that's an exaggeration (夸张), it's too close to the truth. Scientists say teenagers should sleep nine hours
 each night. But that's hard to do.
     Some even "pull all-nighters". These are lazy students who have homework due (到期) the next day
  that they haven't done. In the morning they don't look healthy and you can tell who has been doing it.
     One of my classmates did a survey (调查) on the problem. She found that most kids pull all-nighters to
  finish homework, but some do it for other reasons, such as playing computer games!
     Maybe our lack of sleep is because of laziness-I think I'm a lazy student-or maybe it's because we have
  too much to do in American high schools.
     I usually go to bed around midnight. If I stayed up past 1: 30 a. m, I wouldn't get any work done. I'd be
  falling asleep at my computer. My classes begin at 7:30 a.m. I'm partly awake in my first class. By the
  second, I'm slightly tired and sleepy. By my third class, I'm sleepy. By midday I'm finally wide-awake.
 But by 3: 00 p. m., I'm slowing down again.
     Most American high schools seem to have such a problem.
     High school classes start at 7: 30 a. m., so students have to wake up one and a half hours before that to
  get ready and catch the bus. It's believed that lack of sleep can damage both grades and health.
     Some schools are paying attention. Classes in those schools start at 8:30 a. m.
1. What's the problem talked about in the passage?
    A. Many kids have too much homework to do.
    B. Many teenagers don't have enough sleep.
    C. Many children are crazy about playing computer games.
    D. Many kids are too lazy to finish their homework on time.
2. The underlined expression "pull all-nighters" most probably means _____.
    A. 开夜车
    B. 上夜班
    C. 睡懒觉
    D. 补作业
3. Which of the following is NOT a reason mentioned in the passage?
    A. Laziness.  
    B. Homework.
    C. Housework.  
    D. Computer games.
4. What's the idea suggested at the end of the passage?
    A. Later start of classes.  
    B. Less homework.
    C. Going to bed early.  
    D. Eating healthy food.

根据所给中文意思完成句子，每空只填一个词。