Have you ever heard that some animals do not need any sleep? Butterflies and fish are （例子）. We usually see them not move, but this doesn't mean that they are sleeping. Their body temperatures will （变得）low, and as a （结果）they can't move. Is it surprising?
Do you think that we can live without any sleep? One woman in England （打破）the world record（记录）by not sleeping for eighteen days and seventeen hours. According to doctors, people will （死亡）if they don't sleep for more （比）five days. If we don't get （足够的）sleep, we will feel tired and even be sick. You can find that sleep plays an important （作用）in our health. So, children, please be clever and go to bed much （早）from now on.
Let's look at the following ways to help us get good sleep.
Firstly, exercise. Running, riding bikes or swimming will get you tired. After that, you will sleep better and faster. But don't do exercise right before going to bed!
Secondly, keep your room only for sleeping. Don't eat, watch TV （节目）， use your computer and so on.
