Question

【题目】In the street，you should be careful enough ________ old people down.

A. avoid knocking B. avoiding to knock

C. to avoid knocking D. to avoid to knock

Answer 1

【答案】C

【解析】句意：在大街上，你应该足够小心避免撞倒老人。根据句意，结合固定搭配：be careful enough to do sth,足够小心做某事；avoid doing，避免做某事。故答案为：C.