写作思路：先从介绍运动的好处开头，接着以乒乓球的中心主旨入手，以使文章中心思想鲜明、深刻地表现出来，正文：
Exercise can also contribute to the development of our ability to response agilely. For instance, when you play table- tennis, you must try to reflect as quickly as you can so that you may fight back at the right position at the fight moment.
运动也有助于提高我们的反应能力。例如，打乒乓球时你必须要快速反映，这样你才可以在正确位置反击。
Exercise can also contribute to improving our mood. When you do exercise, you move a lot, and you have to be more active. It helps you become more optimistic.
运动也有助于改善我们的心情。做了运动，活动多了，你也会变得更活跃。它可以帮助你变得更加乐观。
Exercise will fill your life with various contents and make it more colorful.
锻炼会使你的生活变得丰富多彩。
Whats more, exercise will help you get rid of your inertia. If you keep doing exercise regularly, you will never be a lazy person. Therefore, exercise has great effect on ones character.
而且运动可以帮助你摆脱你的惰性。如果你经常锻炼，你永远都不会成为一个懒惰的人。因此，运动对一个人的性格有很大的影响。
In a word, exercise is helpful, important and absolutely necessary.
总之，运动是很有用，很重要，当然也是很有必要的。