The keys to reaching or staying at a healthy weight are regular exercise and good eating habits. Teens should get 60 minutes or more of physical activity a day. Note the word “activity”. As long as you’re getting your body moving, it doesn’t have to mean doing difficult exercise or going to the sports hall every day. All that matters is that each week you get the right balance of activity, including aerobics (有氧运动), strength building, and flexibility (柔韧) exercise. Make exercise a habit by arranging some time every day. On days when you have soccer practice or an aerobics class, you may have no trouble exercising for an hour or more. But most of us are busy, and 60 minutes a day for exercise seems like a lot of time. The good news is that it’s OK to divide it into shorter exercise breaks throughout the day. Just as you might have a healthy snack to stop yourself from getting hungry, exercise snacks can keep energy levels high. So get up 15 minutes early and do some stretching (伸展) activity. Walk fast or run slowly for 15 minutes after lunch. Do the same thing after school — or walk or bike home. Add to that taking the stairs, PE class, and walking between classes during the day, and you’ve probably reached your 60 minutes. Here are five simple ways to make an exercise lifestyle change: 小题1:The writer thinks many people probably misunderstand the word“activity” to be “_______”. A．physical activity B．body movement C．sports hall exercise D．outdoor exercise 小题2:When exercising, the most important fact is ________. A．the time spent on exercise B．the intensity of activity C．the difficulty of exercise D．the right balance of activity 小题3:The author advises dividing activity into shorter exercise breaks because ___. A．exercising for a long time is bad for people’s health B．it has the same effect as soccer practice C．people usually haven’t much time to exercise D．no one can spare lots of time to exercise 小题4:What’s the best title for this passage? A．Regular exercise. B．School exercise. C．Indoor exercise. D．Difficult exercise