【正确答案】 C

【答案解析】此题属于近义词辨析题。选项[A]assure表示“使(某人)确信或放心”，例如：He assured me that he was able to do that，选项[B]confide表示“吐露”，例如：confide the truth to one's parents．选项[C]ensure表示“保证(某事会发生)”(make certain that sth．happens)，例如：I am sorry I cannot ensure you a good post．选项[D]guarantee也表示“保证”但是它的英语解释是promise to make sure that sth．will definitely happen，例如：They have guaranteed that they will repay the money provided by the bank．[C]和[D]在语意上还是有一定的差异，而[C]ensure更符合文义，是正确答案。