第二部分： 英语知识运用 （共两节，满分45分）
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。
21. The most important thing is to keep _____ when you get into difficulties.
A. quiet B. calm C. still D. silent
22. Many of your classmates dislike having to stay up late doing their lessons, _____?
A. do they B. have they C. don’t they D. haven’t they
23. The English teacher told us this morning that we _____ an exam at the end of this month.
A. will have B. would have C. have had D. had had
