Question

【题目】It was ________ that we tried to make him change his mind.

A. paid off B. in vain

C. took off D. in effect

Answer 1

【答案】B

【解析】考查动词短语及介词短语辨析。A. paid off “付清；成功，有回报（Sth pay off.）”；B. in vain“徒劳”；C. took off “脱下；起飞”D. in effect“（指规则、法律等）生效，实际上”，所以该句It为形式主语，that引导真实的主语从句，该句句意：“我们尽力使他改变主意是徒劳的。”，故正确答案为B.