阅读短文，根据短文内容填空。

    We all need to exercise. Doctors say it is good for us. It makes our body strong. And we will feel better about ourselves. We can exercise twice a week. Twenty minutes each time is enough(足够的). There are many ways(方法)to exercise. We can walk, run, play sports or swim. Many people go to special(特别的)places to exercise. These places have a lot of equipment(设备). They exercise with their friends together. Some people have equipment in their homes. Exercising can be fun. How do you exercise?