have had done与had have done区别

题中 i'd have told you 是 i would have told you 不是i had have told you 根本没这个结构B中的 i had have known 也是这样错,直接用 i had known ( 过去完成时对过去虚拟) 就可以了C 其实就是 if i had known 把 ...