A、Giving a lecture. B、Discussing political science. C、Working on a science problem. D、Reading twentieth-century literature. B

M: Hi, Janet. Where were you at lunchtime? I was saving a seat for you in the cafeteria.
W: Oh! Sorry to miss you. But my thirst for knowledge was greater than my pains of hunger!
M. I’ve never had that problem. So where were you?
W: My political science 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: Who is this twentieth-century Socrates?
W: Professor Hall. Have you heard of him?
M: Hm, he does have a good reputation in the Political Science Department.
W: And a well-deserved one! The same students who fall asleep in discussion groups and seminars fight for front-row seats in his lectures.
M: Oh, no! I hope this isn’t catching!
W: You can joke. But it’s great to have a professor who’s not only interesting, but also prepared to give up time for students.
M: I know. They’re rare sort. Maybe I should sit in on his class sometime. Do you think he’d care?
W: Not at all. Lots of students bring their friends, and he says he feels pleased.
M: Well, just to be safe, I think I’U bring my lunch along as well.
W: I’ll make a good student of you yet.