阅读短文，选择正确答案。
During the day we work and play; at night we sleep. Our bodies rest while we sleep. In the morning we are
ready to work and play again. While we are asleep our bodies grow most. Children usually need more sleep. We
can get our lessons better and we feel better too, when we have plenty of rest. Boys and girls need ten hours of
sleep every night when they are eight or nine years old. Our bodies need lots of air when we sleep. If we do not
get enough fresh (新鲜的) air we'll feel tired when we wake up. While in bed we must not cover our heads. If
we do, our lungs (肺) will not get enough fresh air. If we open our windows at night we can have plenty of
fresh air. Cool air is better then warm air. Boys and girls must get enough sleep if they want to grow and be
strong.
1. Our bodies grow most while we are
.
[ ]
A. eating
B. playing
C. sleeping
D. waking
2. Which is the best air for us?
[ ]
A. Hot air
B. Cool air
C. Warm air
D. Dry air
3. Too little sleep makes us
.
[ ]
A. happy
B. hungry
C. tired
D. grow
4. How much sleep should boys and girls of nine years have every night?
[ ]
A. Eight hours
B. Nine hours
C. Ten hours
D. Seven hours
5. What do the lungs need most?
[ ]
A. Fresh air
B. Food
C. Rest
D. Exercise