A、A week. B、Some time. C、One month. D、Two days. B医生问这个症状是最近才开始的还是持续已有一段时间，由病人的回答可知这个症状已有一段时间。故选B。

M: Dr. Wang, I called you last week to make an appointment.
W: Oh, yes. I got it from my nurse. What seems to be the problem?
M: I seem to be short of breath.
W: Do you have a cough?
M: Yes, (16) I have a cough, but I also seem to wheeze a lot.
W: Is this a recent symptom, or have you had it for some time now?
M: (17) I’ve had it for some time, Doctor.
W: Do you suffer from coughing fits or cough a lot?
M: Yes, a lot.
W: Do you bring up phlegm or is it a dry cough?
M: I bring up quite a bit of phlegm. (20) I’ m afraid I might have asthma.
W: What’s the phlegm like?
M: What do you mean?
W: Can you describe the phlegm for me? What colour is it? Is it white, yellow or greenish, and is it foamy or sticky?
M: Yes, (18) it’s yellowish and feels kind of like jelly.
W: Does it have a strange smell or taste?
M:(19) No, I don’t think so.
W: Has there ever been blood in it?
M: (19) Yes, just once I noticed some blood in it.
W: Have you taken any medication lately?
M: Yes, I was on something to thin my blood.
16．What brings the patient to the doctor?
17．How long has the patient had the problem?
18．What does the phlegm look like?
19．Which of the following is NOT true about the patient?
20．What does the patient think he is suffering from?