17.
W: Sorry, sir. The flight is somewhat behind schedule.
M: Thank you. You will tell us as soon as you know something definite,won't you?
Q: What can we learn from the conversation?
正确答案：B
解析：女士说飞机晚点了，故B正确。late即behind schedule的同义表达。

18.
M: I sent a letter to make a reservation for a single room a few days ago.
W: I'm sorry, but your request arrived too late. There are some conferences in town this week and we're full up.
Q: Why couldn't the man book a room as he wished?
正确答案：A
解析：女士回答说，因为这个星期城里有些会议，所以房间都订满了。故A正确。据full up（是订房场景的常用关键词）可作答。