Question 28to 31are based on the following passage. Regular exercise can help you build stronger muscles, shake off illnesses?and make your clothes fit a whole lot better. But there’sanother benefit:even moderate exercise www.docin.com 10 seems to take years off your age. Of course, you cant change your age, but exercise can improve your health so that you look and feel younger than you are. Exercise gives you more energy. Exercise fires up your brain and body so you feel more energetic. Exercise puts your body in a state of excitement,which means more vitality and a greater sense of well being. Daily tasks become less tiring and require less effort. It’s the kind of energy that makes you feel like you are a decade or two younger. Exercise keeps your skin soft and glowing. Researchers studied a small group of adults between ages 20and 84. The frequent exercisers who were over age 40had skin that resembled the younger skin of people in their 20s and 30s. The difference had nothing to do with sun exposure, which would age your skin faster, reported the research team, they guess that exercise creates body substances that help slow aging in skin, though they say more research is needed to learn how exercise works. Moreover,exercise helps you sleep soundly. Restful sleep is like a fountain of youth, and exercise helps you achieve it. Research shows that regular exercisers fall asleep more easily and are more likely to 7experience deep sleep. Exercise tires you out,sure,but there’s v more to it than that. Sleeping well helps all the systems in your body function optimally,so d you’re less likely to suffer sleeplessness. A recent study finds that getting at least 150minutes of exercise per week improves sleep quality by 65%. 28.What do we know about sun exposure according to the passage?