Everyone must go to bed early and get up early, or we won't be healthy and clever.Is this true? Maybe it is.The body must have enough sleep.Children of your age need ten hours'sleep every day.If you don't go to bed early, you won't have enough sleep .Then you can't think properly and can't do your work properly.You will not be clever.Some people go to bed late and get up late.This is not good for them.We must go to bed at night when it is dark.The dark helps us to sleep soundly.When the daytime comes, we must get up.This is the time for exercise.If you lack exercise, you will become weak.Exercise keeps a strong body.Exercise helps the blood flow around inside the body.This is very important.Blood takes food to all parts of our body.The brain also needs blood, we think with our blood.If we keep our body healthy and take exercise, we can think better. The best time to sleep is when   _  .
daytimes it is dark we are taking exercises it is late afternoon