现在完成时和过去完成时变为被动语态是怎么转变的?语法结构是?
问题描述：
现在完成时和过去完成时变为被动语态是怎么转变的?语法结构是?
答
有例句吗?结构 have /has + 过去分词被动语态现在完成时：have/has +been +动词过去分词I have left my book at home.（ 被动）My book has been left by me at home.How long have you kept the book （ 被动）How ...