We all need to exercise. Doctors say exercise is good for us. It makes our heart and body strong. It also gives us more energy(活力）,and we will feel better about ourselves. It’s best to exercise twice a week. Twenty minutes each time is enough.
There we many ways to exercise. You can walk，run, play ball games, or swim. Many people go to special places—fitness centers(健身中心)to exercise. These places have a lot of equipment(设备).Some people buy equipment to exercise at home，but it is very expensive.
Exercise can be fun Friends can exercise together at a fitness center or play sports together. How do you exercise?
1. How often should we exercise?
A. Every day.
B. Twenty minutes a week.
C. Twice a week.
D. Three times a week.
2. _____ is NOT mentioned（提到）in the passage.
A. Swimming
B. Sleeping
C. Walking
D. Playing ball games
