从方框中选择适当的选项补全对话。 A. Thank you, doctor. B. I am not feeling very well. C. Good afternoon. D. Is it serious? E. Do you have a headache? A: Good afternoon, Dr. Smith. B: 1______ Sit down, please. What's wrong with you? A: I don't know. But 2______. B: You look pale. 3______ A: Yes. B: Er … Let me check you over first … Oh, you have the flu. A: 4______ B: Don't worry. Nothing serious. Take this medicine three times a day. A: 5______