听力原文：M: Hi, Susan. Where were you at lunch time? I was saving a seat for you in the canteen. W: Oh, sorry to miss you. But my thirst for knowledge was greater than my hunger for food. M: Ha. I never had that problem. So where were you? W: My physics class ran overtime. M: That's been happening quite a bit lately, hasn't it? W: I guess so. Actually what happens is that a bunch of us hang around for a while after class to talk with our professor and ask him questions. M: Oh, the professor is m popular. Who is he? W: Professor Hall. Have you heard of him? M: Hm, he does have a good reputation in the physics department. W: And a well deserved one. The same students who fall asleep in the discussion group in seminars fight for front row seats in his lecture. M: Oh, no. I hope he isn't catching. W: You can joke. But it's great to have a professor who is not only interesting, but is prepared to give up time for students. M: I know. There I really agree. Maybe I should sit in on his class some time. Do you think he would care? W: Not at all! Lots of students bring their friends and he says he feels flattered. (23)