第二部分：英语知识运用(共两节。满分45分)
第一节：语法和词汇知识(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。
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. The birds ran away all directions they caught sight of a man coming near.
A. in; the instant B. to; the moment
C. from; on the instant D. toward; at the moment
