为了保持健康,我们最好一周运动至少三次.
To keep healthy, we had better exercise three times a week.
Something is wrong with him.He looks (worry).
This car can run by (it),so it's very expensive.
Why not consider (go) swimming this weekend?
A good (listen) will help you a lot when you study.
Children should go to bed before nine every light,or they will be (sleep) in class.