拓展:have been,has been, had been
1.解釋?zhuān)篽ave/has/had+been 都是完成時(shí)。
2.區(qū)別:has/have been是現(xiàn)在完成時(shí),has用于第三人稱(chēng)單數(shù); had been過(guò)去完成時(shí),跟前者相比,比前者更為過(guò)去;
3.例句:
�。�1)He has been doing this work for a period of time.
�。�2)I want to have this book.
�。�3)Have you pass the math exam?
�。�4)Do you ever had a thought that you can win this game?