复杂被动语态（进行被动与完成被动）

外研版必修第三册 Unit 3~4，选择性必修第二册 Unit 2~3 重点语法。

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一、结构对照

语态形式	结构公式	例句
现在进行时被动	am/is/are + being + done	The new library is being built now.
过去进行时被动	was/were + being + done	The bridge was being repaired when I passed by.
现在完成时被动	have/has + been + done	Great changes have been made in our hometown.
过去完成时被动	had + been + done	The work had been finished before the manager arrived.

注意

进行时被动语态必须包含 being；完成时被动语态必须包含 been。