单项选择题
M: I need three stamps and an envelope please. W: Sorry, Sir. You’ re at the wrong window. Go to Window 7, please.
A. In a restaurant. B. In a hospital. C. At a post office. D. At a railway station.
A. 20 minutes before departure B. 30 minutes before departure C. 45 minutes before departure D. 60 minutes before departure