W: Now,Mr. Martin. I've just read your own doctor's report. So you haven't been feeling very well lately, is that right? M: It's... it's my leg, doctor. My right leg. I keep getting a strange pain in it. W: Could you tell me what the pain is like? M: It's like... like boiling water running down my leg. It's been getting worse lately, too. I've been losing sleep. W: You mean the pain's been keeping you awake? M: Yes, that's right. It's been keeping me awake. W: Now, tell me, how long have you had this trouble? M: The pain? For about a year now. W: Hmm... Have you been getting tired lately after you have had a walk? For example, have you been getting a big short of breath, perhaps? M: Why, yes! Yes, I have, doctor! W: Hmm... I think we'd better give you a few tests here in the hospital. M: Do you think it's serious,doctor? W: Probably not. M: But... Doctor Cook, my local doctor, thinks it's only that I've been working too hard lately. W: That could be the reason. Don't worry, we'll find out soon., Question: What has caused the trouble? (A) The woman doesn't know yet. (B) He was burnt by boiling water. (C) He has tired himself out in his work.
(A) The woman doesn't know yet.