had been 的意思和用法?

had been 的意思和用法? has been 和 had been 的用法和差别 英语中had 和 had been 的用法? have has had或 having +been 的区别和用法 been to的意思和用法是什么 have been in的用法和意思 请问HAS BEEN和 HAVE BEEN HAD BEEN的用法以及分别加DONE后的用法 had been 用法. have been in的用法和意思是什么 求have been doing的意思和用法 have been doing 和have done 还有had done三者的区别,用法 been和been to的用法