填空题
Wang Ping: You are not looking well, David. (56) ? David: I'm afraid that (57) Wang Ping: You ought to take some medicine and go back to bed, I think. David: Thank you, Mr. Wang. But (58) ? Wang Ping: Of course. How are you going back? David: By bus. Wang Ping: (59) David: It's very kind of you. (60) ? I want to buy some medicine. Wang Ping: No problem.