2.被動語態(tài)的基本結構：
主語+be +過去分詞(+by+動作的發(fā)出者）
① 一般現(xiàn)在時：am/is/are+過去分詞
如：
Trees are planted every year.
② 現(xiàn)在進行時 am/is/are+ being +過去分詞
如：
The road is being repaired.

③ 現(xiàn)在完成時 have/has + been +過去分詞
如：
The work has been finished.
④ 一般過去時 was/were + 過去分詞
如：
The story was told by him.
Many birds were killed last year.
⑤過去進行時 was/were+ being + 過去分詞
如：
The new house was being painted when I got home.
⑥過去完成時 had +been+ 過去分詞
如：
He told me that the work had been finished.
⑦一般將來時will +be + 過去分詞
如：
The problem will be discussed tomorrow.
⑧ 過去將來時 would/should +be +過去分詞
如：
He said that the Christmas tree would be put up soon.
⑨情態(tài)動詞的被動語態(tài)
情態(tài)動詞+ be +過去分詞
如：
The problem must be solved soon.
Children should be taught to love animals.