单选题 During the day we work and play, and at night we sleep. Our body rests while we are asleep. In the morning we are ready to work and play again. Our body grows most while we are asleep. Children who are tired usually need sleep. We can get better at our lessons after we have had plenty of rest. Boys and girls who are eight or nine years old need ten hours of sleep every night. Our body needs plenty of air when we sleep. While in bed we must not cover our head. Our lung needs to get enough fresh air. If we open our windows at night, we can have plenty of fresh air. Boys and girls who want to be strong must get plenty of sleep.

单选题 Our body grows most while we are
【正确答案】 C
【答案解析】[详细解答] 根据本文第四句可知人睡觉的时候身体在长。
单选题 Too little sleep makes us
【正确答案】 A
【答案解析】[详细解答] 这是一个常识，阅读全文能立即得到答案
单选题 What may cause us to feel tired in the morning?
【正确答案】 B
【答案解析】[详细解答] 根据本文最后几句话可知晚上睡觉时肺部没有吸收新鲜空气，人会觉得累。
单选题 How many hours of sleep should nine-year-old children have?
【正确答案】 C
【答案解析】[详细解答] 根据本文第七句话可知答案。
单选题 The best title of this passage is______.
【正确答案】 A
【答案解析】[详细解答] 根据全文分析，主要讲述的是休息睡眠与人的身体的关系，因此A为最佳答案。