Question

【题目】We must try our best ________ pollution ________again.

A. to stop; happen

B. to stop; from happening

C. stopping; happening

D. stopping; happen

Answer 1

【答案】B

【解析】句意：我必须尽最大努力阻止污染再次发生。try one’s best to do sth尽最大努力做某事，故第一空用动词不定式to stop。stop sb from doing sth阻止某人做某事，故用第二空用from happening，故选B。