21. Doctor: What seems to be the problem?
Emily: I have a runny nose and a sore throat.
Doctor: ___________
Emily: I have been like this since yesterday morning.
Doctor: All right. Here is my prescription.
(A) How long has this lasted?
(B) What kind of medicine are you taking?
(C) Don’t stay up late and try to drink more water.
(D) Take medicine three times a day.