请问,现在完成时比如说have kept 和have been done.那如果是have eaten中间为什么不加be

请问,现在完成时比如说have kept 和have been done.那如果是have eaten中间为什么不加be had done 是过去完成时,have done是现在完成时,那have been和had been呢?be不是动词呀 请问HAVE SB DONE 不表示现在完成时 have been done 和 to be done have done是现在完成时 have been done 是不是现在完成时的被动吖 问下被动语态问题,have been done 是现在完成时的被动语态,那we have done this homew have done和have been have been done和 have done 被动语态be done中 be是什么词性?还有现在完成时的被动语态have been done 中have been是什 have been done 和 have been doing have been done与be done的区别和用法 must have been done/must be done