第一节 单项选择（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. If we expect ________ much cleaner world, we should attract ________world’s attention to protect the world.
A. a; a B. a; / C. a; the D. the; /
22. What he said didn’t mean to hurt Mary, but he felt ________ it differently.
A. he could express B. he could have expressed
C. he would express D. he must have expressed
