第二部分：英语知识运用（共两节，满分35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。
21. Some people fear that ____air pollution may bring about changes in _______ weather around the world.
A. /; the B. the; / C. an; the D. the; a
22. ____________ work has been done to improve people’s living standard.
A. Many B. A great many C. A great deal of D. A large number of
