david： susan, you like sports, don”t 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 don”t have time any more.
　　susan： that”s too bad! exercise is very important.
　　david： i know. i am getting fat, you see. anyway, i don”t want to be heavy.
　　susan： well, i”m 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 o”clock, at the swimming-pool?
　　david： all right. good-bye!
　　susan： good-bye!