(2013·四川省南充市二模) him not to do so, he wouldn't have made such a serious mistake.
A. If I persuaded
B. Did I persuade
C. Had I persuaded
D. If I should persuade
网友回答
A. If I persuaded
B. Did I persuade
(答案→)C. Had I persuaded
D. If I should persuade
解析：选C 考查倒装、省略和虚拟语气。根据“wouldn't have made”可知，此处表示与过去事实相反的假设，因此从句用if引导且用过去完成时；省略if并将had提前就构成了省略if的虚拟条件句，且构成了倒装结构。