题目内容：

Exercise is the best way to stay healthy. But few people get enough exercise. Only 20% of Americans get 150 minutes of physical activity every week. More than 80 million Americans over 6 years old are not active (活跃的).

Many US schools cut (削减) PE classes. Only 15% of schools have this class at least three days a week.

This year, the US National Institutes of Health (NIH) starts an important study. It will show the things happening inside a body after exercise. The NIH hopes to tell people that exercise is a kind of good medicine.

The study will run for six years. It studies a group of about 3,000 people. They are from the 11-year-olds to the old. The study has shown many nice changes in the body during and after exercise so far.

And the study has also shown that housework can be physical exercise. “Cutting the grass, cleaning rooms, washing the car — all of these are exercise,” says a scientist. “Exercise isn’t just throwing a ball into a basket.”

1.What do the first and second paragraphs mainly tell us?

A. How to stay healthy in our daily life.

B. Children under 6 years old are not active in their life.

C. Many US schools don’t have enough PE classes.

D. Most Americans don’t get enough exercise.

2.Why does the US National Institutes of Health start the important study?

A. To tell people exercise is important.

B. To show people some useful exercise.

C. To call on students to do more exercise.

D. To ask people to start doing housework.

3.Which is TRUE about the study?

A. It will run for half a year.

B. It only studies the middle school students.

C. It has shown the body changes during and after exercise.

D. There are three hundred people taking part in the study.

4.Which of the following is NOT mentioned (提及) in the passage?

A. Cutting the grass.

B. Doing some cleaning in the house.

C. Planting some trees in the garden.

D. Washing the car.

5.What’s the best title for the passage?

A. An important study on exercise.

B. Doing housework is helpful.

C. The school students and exercise.

D. A kind of medicine for the old and the young.