A、Brother and sister. B、Mother and son. C、Teacher and student. D、Classmates. D人物关系判断。对话中两人谈论的是考试、复习功课以及考试时间等话题，可推断出他们应该是同学关系。

M: Susan, do you know when Professor Jones’ Biology Final is?
W: Next Tuesday.
M: Next Tuesday! That’s less than a week away, and I have got things planned for this weekend.
W: Haven’t you been studying all along?
M: I have kept up with my lecture notes, but I haven’t reviewed at all.
W: Then it’s your own fault. The date of the final is clearly marked on the course outline.
M: I suppose you are right, but doesn’t it seem awfully early for a final?
W: A little, but it should actually help us out. After we have finished with it, we can concentrate on our other finals.
M: Are you ready for it?
W: I think I am. I’m going to review some more of course.
M: Do you think we could study together sometimes this week?
W: I don’t see why not. Are you doing anything tomorrow night?
M: I can’t tomorrow. I am going out with some guys to that new nightspot downtown.
W: Well, how about the following night?
M: No, I can’t Saturday either.  My sister and her husband are coming to town and I want to show them around.
W: Sunday, then?
M: Well, I’ll probably sleep all morning and in the after- noon I want to go to the football game. Also that night I have to write and type up a paper for another class.
W: Michael, that leaves Monday, the night before the test.
M: Actually, I’ve got plans for Monday night too.  How about Early Tuesday morning?
W: Michael, the test is on Tuesday morning.