Early to bed, early to rise, makes a man healthy, wealthy and wise.
This is an old English saying. Have you heard of it before? It means that we must go to bed early and get up early in the morning. Then we shall be healthy. We shall also be rich (wealthy) and clever (wise).
This is true. The body must have enough sleep to be healthy. Children of young age should have ten hours’ sleep every night. Children who do not have enough sleep cannot do their work very well. They will not be wise and they may not become wealthy!
The body also needs exercise. Walking, running, jumping, swimming and playing games are all exercise. Exercise keeps the body strong. Exercise also helps the blood (血液) to move around inside the body. This is very important. Our blood takes food to all parts of our body. The head also needs blood .Exercise helps us to think better!
小题1:If we get up early and go to bed early , we’ll _________ .
A．have enough exercise
B．be healthy
C．think better
D．have strong blood小题2:If a child doesn’t have 10 hours’ sleep, maybe he _____ .
A．becomes wise
B．won’t do well in his work
C．goes to school in time
D．has enough sleep小题3:A person needs exercise because _______ .
A．it makes him healthy
B．he has a lot of homework to do
C．he is strong enough
D．he does exercise小题4:Exercise makes the ______ move quickly and smoothly(流畅)
A．body
B．blood
C．children
D．head小题5:Which of the following if Not TRUE?
A．Exercise does good to a person’s head
B．A student should have 10 hours’ sleep
C．It’s good for you to get up early and go to bed early.
D．If you have enough blood, you’ll be wise.
气体,B为真空（如图① ）,现把隔板抽去,A中的气体自动充满整个容器（如图②）,这个过程称为气体的自由膨胀,下列说法正确的是 （）