第一节 单项填空（共15小题;每小题1分，满分15分）
从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
例：We _______last night, but we went to the concert instead.
A. must have studied B. might study
C. should have studied D. would study
答案是C
21. —Do you mind my opening the window? It’s a bit hot in here.
--________, as a matter of fact.
A. Go ahead. B. Yes, my pleasure
C. Yes, I do. D. Come on
