1 . Teenagers' busy life can cause them to see exercise as a waste of time. However. the belief is far from true. Exercise is important for teenagers because it not only promotes physical health. but also improves mental health.

Exercise plays an important role in a teenager's mental health. Teenagers who exercise tend to have a better body image than those who don't, which helps build confidence and makes one feel more comfortable. This also helps one to accept his or her looks. Although physique(体形)is not as important a factor as health,it can strongly affect teenagers' mood and attitude. A healthier and fitter body will build a greater sense of confidence in the body image.

Another mental benefit from exercise is the feel-good endorphins(内啡肽)that come along with it. The body produces endorphins naturally when one exercises hard that are commonly referred to as"a happy chemical". They can produce a feel-good effect and create a sense of emotional well-being during and after exercise. They can make physical activities more enjoyable. They can also reduce stress and relax one to a point at which it is even easier for one to fall asleep.

Many students say that they are too busy with schoolwork to exercise. but they don't realize that exercise can improve their mental performance. Exercise such as walking and jogging increases the flow of oxygen to the brain and heart. Teenagers who exercise regularly tend to have the ability to think more clearly and faster, In addition, teenagers that exercise regularly tend to be more focused and perform better in school. Various mental issues can be aided by exercise as well, For example, one who suffers from anger issues may look to exercise as an outlet. Teenagers who struggle with anxiety and depression can also find a healthy outlet through exercise.

1. What do we know about a good physique?

A．It can make teenagers more confident.

B．It is more important than health.

C．It can't affect teenagers' mood and attitude.

D．It can change teenagers' looks.

2. What does the underlined word "it" in paragraph 3 refer to?

A．Body.

B．Benefit.

C．Exercise.

D．Endorphin.

3. Which word best describes the author's attitude to exercise?

A．Negative.

B．Positive.

C．Uncaring.

D．Worried.

4. What is the text mainly about?

A．Teenagers' problems with exercise.	B．The importance of mental health.
C．Teenagers' mental performance.	D．The mental benefits from exercise.