英语用法问题was were/ has been/ had been/ have been 有何不同?另外过去时和过去分
have been +过去分词,和had been+过去分词,有什么区别?
几个英语用法HAVE BEEN 和 HAS BEEN 有什么不同 WERE怎么用?
英语have been studying过去进行?用法?
过去现在时 have /has been doing和have/ has +过去分词的区别
英语,has been和 had been
have/has been+过去分词是什么时态?
have been studying过去进行?用法?
过去式和过去分词有什么不一样 如be的过去时were/was和过去分词been有什么不同处
英语系动词的用法.英语中有 was .is,are,has been,have benn,will,would,were
have has had或 having +been 的区别和用法
was changed和has changed ; have been和had been ; have done 和 h
have been doing 和have+过去分词有什么不同?