《投资指南》:We have done thing we ought not to have done and___undone things we ought to have done.

We have done thing we ought not to have done and___undone things we ought to have done. the only thing we have to fear is fear itself." have done 如何翻译 meant to have done have sth done 为什么用done呢 have sth done的用法 have done表示现在完成式？ have sth done是什么语态？ must＋have done 句型 have sth done 的过去完成时?