A、Professor and student. B、Professor and assistant. C、Librarian and student. D、Fellow students. D①选项都是表示身份的名词短语，由此可以推断问题与人物关系有关。

M: Morning, Myra.
W: Oh hi, Arthur! [6]/[10] You’re taking Ecology 311, too?
M: Looks like it. [6]It’s my only elective course this term.
W: Really? What happened?
M: Oh, I just took too many my second year, and now I’ve got to pick up all the required courses I’ve been ignoring. University’s just too much fun, I guess. And it has helped me decide my major, finally.
W: What’s it?
M: I’m going for my BA in business administration.
W: So, why 311? An ecology course isn’t going to help you in your office job at some corporation.
M: [7]Probably not, but... it still seems interesting—and important. We all need to know about the environment, no matter what we do for a living.
W: Yeah, you’re right. And maybe you will be able to use it. Maybe you’ll end up working for a green company or something.
M: Could be. There’s more and more of those every day. Is that why you’re taking this?
W: [8]Well, it’s not an elective for me. I need 311 for my BS program. We need several cross-field courses to "broaden our understanding", and this is one of them. Actually, though, I’m looking forward to this course: "Nature’s Influence on Man—Man’s Influence on Nature"! Sounds like a really useful topic, doesn’t it? And Dr. Forsythe is supposed to be a very engaging lecturer.
M: Yeah. Sure.
W: Did you pick up your textbook yet?
M: No. [9]I’ve been looking for a secondhand copy before I spring for a new one. It’s expensive—forty-five bucks!
W: They all are, aren’t they? Why do poor college students have to pay so much for their textbooks? It ain’t fair.
M: It’s just economics. Nobody reads them except the students that take the courses. The publishers probably didn’t print more than a few hundred copies of our text, you know.
W: I suppose you’re right. Where you gonna find a used copy? At the bookstore?
M: They don’t have any there now—I checked. I put up some notes on the Science Building bulletin boards yesterday. Maybe someone there’s got one they don’t want to keep anymore.
W: Well, uh, if you hear about two of them, will you let me know? I’d like to save a little money, too.
M: Sure. If I do, I’ll buy it for you and you can pay me back. How much are you willing to pay?
W: Oh, anything under thirty-five dollars will be fine. A penny saved is a penny earned. But if you haven’t found one by next Monday, I’ll have to buy a new one then, so email me Sunday night either way, will you?
M: You bet. Oops! [10]It’s almost 8:00. Here comes Dr. Forsythe.
6．What is the possible relationship between the two speakers?
7．Why does the man take Ecology 311?
8．What’s the most important reason for the woman’s taking Ecology 311?
9．Why does the man want to buy a secondhand textbook?
10．What will the speakers probably do soon?