【正确答案】 B

【答案解析】[听力原文]
W: John, could you house-sit for me while I"m away on vacation?
M: Oh, sure. You house-sat for me before.
Q: Why does the woman ask John to house-sit for her?

[解析] 女士问，“我度假时，你能帮我照看房子吗?”据此推断，女士是因为要去度假才请这位男士帮她照看房子的。故正确为B。

【正确答案】 A

【答案解析】[听力原文]
W: You look so exhausted. There"s always too much work for you to do. They won"t hire more people?
M: No. They want to keep the cost down.
Q: What can we infer from the conversation?

[解析] 女士说，“你看上去很疲惫，你总是有很多工作要做……”因此，可以推断 The man is so tired because he has to do much work. A为正确。

【正确答案】 D

【答案解析】[听力原文]
M: Sally, what"re you going to be? Are you going to be a computer engineer?
W: Of course. I"m fond of computers, and they all call me a computer genius.
Q: What will the woman do in the future?

[解析] 男士问，“Are you going to be a computer engineer?”女士回答，“Of course. I"m fond of computers, and they all call me a computer genius.”可以推断，女士将来想成为一名计算机工程师。故为D。

【正确答案】 C

【答案解析】[听力原文]
M: How much are these mice?
W: They used to be 10 dollars each, but now it"s 15 dollars for two.
Q: How much will the man pay if he buys four mice?

[解析] 这是数字计算题。根据女士的回答“They used to be 10 dollars each, but now it"s 15 dollars for two.”所以，男士如果买四个鼠标，他需要付30美元。故为C。

【正确答案】 A

【答案解析】[听力原文]
M: I need to relax. Maybe we can take a break after the paper.
W: I hope so, but we have to prepare well for the paper now.
Q: What"re they doing now?

[解析] 根据男士和女士的对话，他们只有在完成论文后，才能休息和放松。所以，可以推断，他们此刻正在忙着写论文。故为A。