听力原文：M: Hi, Karen. Your roommate told me that I could find you here. What are you doing here?: W: What does it look like I am doing? M: Well, it looks like you are watching television. But we have a math mid-term tomorrow, so I thought you'd be studying for it and maybe I can study with you. W: Oh, we'll, I was just taking a break. This math stuff gives me a headache if I work on it too long. M: I know what you mean. I've been working on it for three hours through it already. I encounter with the sample problems. I just don't get some of them. W: But I can't believe you are coming to me. I mean you do know what I got on the last test, don't you? M: Yeah, I know. You told me. I just thought two heads might be better than one. W: Eah, that's nice idea. But... you know, I wish I knew that person in our class who got a hundred on the last test. She didn't miss a question. Umm... was it Elizabeth? M: Oh yeah, Elizabeth! She is a friend of mine. She'd be a big help right now. Why don't I give her a call? W: What! At this hour? It's already ten thirty. I don't wanna impose on her. M: Yeah, I guess you are right. But you know what she owes me a big favor. Let's at least give her a call and see what she says. Maybe going over some of the problems with us would help her review the material. W: It's worth a try. (20)