题目内容：

During the day we work and play, and at night we sleep. Our body rests when we sleep. In the morning we are ready to work and play again. Our body grows when we are sleeping. Children usually need sleep, too. We can do better in our work after having a good rest. Boys and girls who are eight or nine years old need ten hours of sleep every night. Our body needs enough air when we are sleeping. If we don’t get enough fresh air, we will feel tired when we wake up(醒来). While in bed we must not cover(盖住) our head, our lungs need to get enough fresh air. If we open our windows at night, we can get lots of fresh air. Cool air is better than warm air.

根据短文内容，选择正确答案。

1.Our body grows when we are ___________

A. eating     B. playing

C. sleeping   D. exercising

2. If we don’t get enough sleep, we will feel ___________.

A. tired B. hungry   C. happy D. angry

3.How many hours of sleep should 9-year-old children have every night?

A. 8 hours      B. 9 hours

C. 10 hours      D. 11 hours

4.What do the lungs need most?

A. Fresh air    B. Covering

C. Warm air     D. Exercise

5.When we are sleeping, we shouldn’t ____________.

A. open the window  B. cover our head

C. need fresh air  D. have a good rest.