第二部分：语言知识运用（共三节，满分55分）
第一节 单项填空（共15小题；每小题1分，满分15分，请将答案涂在答题卡上）
21.The boy wanted to ride his bicycle in the street; but his mother told him ________.
A. not to B. not to do
C. not do it D. do not to
22.We must do whatever we can ________ those who are in trouble.
A. to help B. help
C. helping D. do help
