根据下面的提示，以Talking about Having Sports为题编写一段对话(字数：80--120)。
提示：
Susan每天下午参加体育活动。她喜欢游泳，每星期游泳一次。David在中学时代也常游泳，但现在没有时间，人也开始发胖了。Susan邀请David当天下午一起去游泳，并约定下午三点在游泳池见面。
Talking about Having Sports
David： Susan, you like sports, dont you?
Susan： Yes. I have sports every afternoon.
David： Do you often go swimming?
Susan： Yes, I go swimming once a week.
David： I used to swim at middle school, but I dont have time any more.
Susan： Thats too bad! Exercise is very important.
David： I know. I am getting fat, you see. Anyway, I dont want to be heavy.
Susan： Well, Im going to swim this afternoon. Do you want to go with me?
David： OK! I really need more exercises. When and where shall we meet?
Susan： How about three oclock, at the swimming-pool?
David： All right. Good-bye!
Susan： Good-bye!