摘要
我们都想知道长期保持健康的秘诀。的确，要保持健康是有个秘诀，那就是要经常锻炼。为什么这么说呢？阅读下文后，你就会找到答案。
Have you ever heard the expression use it or lose it＂？ It＇s true! If you don＇t use your body, you will surely lose it. Your muscles will become flabbyl and weak. Your heart and lungs won＇t function efficiently, and your joints will be stiff and easily injured. Inactivity is as much of a health risk as smoking!
