第二部分：英语知识运用（共两节，满分35分）
第一节：单项填空（共15小题；每小题1分，满分15分）
21．How I regret _______ so much time playing games, _______ I should have studied.
A. to waste, which B. wasting, which
C. having wasted ， when D. having been wasted, when
22.-What do you think of the book?
-Oh, excellent. It is worth _________ a second time.
A. reading B. to read
C. being read D. to be read
