He rangs almost the best pupils of his grade,it's surprising that he should have failed in this exa句中should怎么理解?
问题描述：
He rangs almost the best pupils of his grade,it's surprising that he should have failed in this exa
句中should怎么理解?
答
should have done sth,是虚拟语态中的过去时态表示方法.
放在这个句子里的话,过去时,是因为“this exam”已经结束；而用虚拟语态,是结合上下文,他是这一级学生中最好的之一,所以,如果他在这次考试中失败会令人非常惊讶,it 后面的is,是主句的一般现在时了.
希望我的解答够清晰