现在完成时的被动语态结构是什么？
现在完成时的被动语态结构是：have（has）been+过去分词。
例如，The tree has been cut down already.
That math problem has not been worked out yet.
Has your homework been finished today?
现在完成时的被动语态结构是：have（has）been+过去分词。
例如，The tree has been cut down already.
That math problem has not been worked out yet.
Has your homework been finished today?