题目内容：

Everyone knows that exercise is important. We all need to exercise. Doctors say it's good for us. It keeps body strong.    When the daytime comes, we must get up. This is the time for exercise. Exercise means doing things with the body. There're many ways to exercise. You can walk, run, swim, skate, or play ball games. Make sure you exercise in the following ways : You have to like what you're doing.  Exercise enough but not too much. It's good to exercise twice each week. Thirty minutes each time is enough. Try all kinds of things until you find one, two or three sports that are suitable for you.     Exercising can be fun. Friends can exercise together at a fitness center. and they can play sports together. How do you exercise?

Why	Exercise can keep us 1.__________,so we need to exercise.
When	The best time for exercise is in the 2.__________.
How	There are 3._______ways to exercise according to(根据)the passage.
It’s enough for you to exercise4.__________minutes every time. Exercising5.__________a week is good.