17.
M: Can I borrow your math textbook? I lost mine on the bus.
W: You've asked the right person. I happen to have an extra copy.
Q: What does the woman mean?
正确答案：B
解析：本题关键在于听懂习惯表达“你问对人了（You've asked the right person）。”男士向女士借数学课本，女士说“你问对人了。我碰巧有一本多余的。”说明她可以帮助男士。A是对You've asked the right person的曲解。

18.
W: Hello, this is Dr. Gray's office. We're calling to remind you of your 4:15 appointment for your annual check-up tomorrow.
M: Oh, thanks. It's a good thing you've called. I thought it was 4:15 today.
Q: What do we learn from the conversation?
正确答案：A
解析：本题关键在于抓住时间的对比和口语表达“It's a good thing you've called. I thought... 幸亏你打来电话，我还以为……”体检预约在第二天，但男士以为是当天，故答案为A（他差点弄错了预约的日期）。