A、In the coffee shop. B、Discussing physical problem in the classroom. C、Working on a science problem at home. D、Reading 20th cen

M: Hi, Margaret, where were you at dinner-time? I was saving a seat for you in the coffee shop.
W: Oh, sorry to miss you. But my thirst for knowledge was greater than my pains of hunger.
M: So where were you?
W: My physical science class ran overtime. Actually, what happens is that some of us hang around for a while after class to talk with our professor and ask him questions.
M: Who is this 21st century’s Newton?
W: Professor Greg, have you heard of him?
M: Yes. He does have a good reputation in the Physical Science Department.
W: And a well deserved one. The same students who Pall asleep in discussion group fight for front-row seats in his lectures.
M: Oh, on. I hope this isn’t amazing.
W: You can joke. But it’s great to have a professor who’s not only interesting but prepares to give up time to students.
M: I know it is really rare. Maybe I should sit in his class some time. Do you think he’d care?
W: Not at all. Lots of students bring their friends. He says he feels flattered.
M: Well, just to be safe, I think I’ll bring my dinner along as well.
W: I’ll make a good student of you yet.