21.
根据短文内容，选择正确答案。
It's important for us to be healthy. Everybody wants to be healthy. But how can we keep healthy? Here is some useful advice. First, you should eat fruit and vegetables three or four times a week. There are some kinds of vitamins our bodies need. We should not eat too much meat. Then eat some tofu every day because it's good for people, both the young and the old. Milk is also necessary(必要的), especially for women. So you should have milk twice a day. It can help you to be strong. Next, doing more exercise is better. You can do morning exercises or evening exercises. After supper you should take a walk.
-
（1）
How often should we eat fruit and vegetables?
A . Once or twice a day.
B . Two or three times a day.
C . Three or four times a week.
D . Three or four times a month.
-
（2）
Tofu is good for .
A . young people
B . old people
C . students
D . young and old people
-
（3）
We should have twice a day.
A . fruit
B . milk
C . tofu
D . vegetables
-
（4）
To be healthy we can NOT .
A . do morning exercises
B . do evening exercises
C . take a walk after supper
D . eat too much mean
-
（5）
The passage mainly tells us .
A . how to keep healthy
B . what health is
C . why health is important
D . how often you should exercise
