题目内容：

    Teenagers’fitness is now a major concern, and physical exercise is very important. It reduces stress and improves fitness. Exercise makes your body strong, and helps you to keep the right body weight. Sports scientist Dr. Helen Lopez offers the following advice to teenagers: “First, you need to find out your present level of fitness. Then you can design a programme that will help you become healthier.”

Dr. Lopez suggests that there are three levels of fitness that need a change of lifestyle. “Overweight” means that the person gets very little exercise and often has a serious weight problem. “Inactive” means that the person does not join in many physical activities, but is not seriously overweight. “Active” refers to people who take part in sports and other physical activities, but do not have a high fitness level.

According to Dr. Lopez, overweight teenagers should work out to keep healthy. “Ride a bike, play volleyball or basketball for a while, and go for a twenty-minute walk each day. All these will help to burn calories.” Inactive teenagers should do similar activities, but add some bending and stretching exercises, such as push-ups and sit-ups, starting with twenty of each a day. “Inactive people can take a little more exercise than overweight people because their bodies are stronger,” Dr. Lopez said. The same rule applies to (适用于) active teenagers.

Dr. Lopez suggests one hour a week or more on running and other forms of intensive exercise, together with fifteen minutes a day spent on stretching and bending activities.

“These are really important in order to prevent injuries,” Dr. Lopez said. Some weight-training and other body-strengthening exercises could also be planned in the programme in order to increase the person’s strength.

1.What can we learn from the passage?

A.Active people always have a high fitness level.

B.Overweight people always take more exercise.

C.Inactive teenagers are not seriously overweight.

D.Keeping fit means changing teenagers’lifestyle.

2.Which of the following is NOT mentioned in the text?

A.Physical exercise can make the teenagers grow taller.

B.Physical exercise can help teenagers become healthier.

C.Physical exercise can help to burn up calories.

D.Physical exercise can increase teenagers’strength.

3.What exercise should people do in order to prevent injuries?

A.Walking.

B.Stretching and bending.

C.Riding.

D.Weight training.

4.What is the best title for the passage?

A.Doing Exercise B.Teenagers’Fitness

C.Different Lifestyles D.Overweight Teenagers