Question

【题目】All Mrs Smith's efforts to tidy the room were _____ because her grandson soon made a mess of it again.

A. at all costs B. at random

C. in vain D. in return

Answer 1

【答案】C

【解析】

试题分析：考查介词短语辨析A. at all costs不惜代价；B. at random任意地；C. in vain浪费地；D. in return回报；句意：史密斯女士清扫屋子的所有努力白费了因为她的外孙又弄乱了，根据句意可知选C项。

考点 : 考查介词短语辨析