题目内容：

    David Smith，12，usually gets up at about 7：40 am. He goes to bed_______ and only gets about seven hours of sleep each night._______waking up in the morning isn't easy for him.“I often feel _______ in class，” David says.

Children from 5 to 12 years old _______at least ten hours of sleep each night.But scientists say that a lot of children   don't get _______ sleep.Even some of them sleep _______ than eight hours every day.

What is keeping children _______at night？We made a survey in David's school.We collected the answers of all the students _______ this question.The answers show that the big stealer(偷窃者)is the _______.68% of the students in this school said they went online before________．Most boys and girls said they used the________ to chat(交谈)with friends.

Scientists say if a person has a good sleep，he or she will ________ well next day.If students sleep well at night，________ will do better in math and writing tests.

It's ________too late to change your sleeping habits.Go to bed early and keep doing that for a week.Then see ________ you feel.You will find you become different.

1.A.early B.soon C.again D.late

2.A.Because B.If C.So D.When

3.A.excited B.happy C.lucky D.tired

4.A.do B.decide C.need D.seem

5.A.popular B.healthy C.wonderful D.enough

6.A.more B.less C.best D.good

7.A.getting up B.cutting up C.waking up D.staying up

8.A.of B.with C.to D.by

9.A.computer B.dictionary C.magazine D.television

10.A.going home B.going to school C.going shopping D.going to bed

11.A.e­mail B.telephone C.bicycle D.Internet

12.A.dance B.learn C.sing D.jump

13.A.we B.he C.she D.they

14.A.always B.never C.often D.ever

15.A.what B.when C.how D.where