2018年高中士兵考军校-英语知识点汇总（四十三）

　　被动语态讲解

　　（一）、被动语态的构成形式

　　1. 被动语态的基本时态变化

　　被动语态通常为十种时态的被动形式， 被动语态由be＋过去分词构成，be随时态的变化而变化。以do为例，各种时态的被动语态形式为：

　　1） am/is/are +done （过去分词） 一般现在时

　　例Visitors are requested not to touch the exhibits.

　　2） has /have been done 现在完成时

　　例All the preparations for the task have been completed， and we're ready to start.

　　3） am/is /are being done 现在进行时

　　例A new cinema is being built here．

　　4） was/were done 一般过去时

　　例I was given ten minutes to decide whether I should reject the offer.

　　5） had been done 过去完成时

　　例 By the end of last year， another new gymnasium had been completed in Beijing.

　　6） was/were being done 过去进行时

　　例A meeting was being held when I was there.

　　7） shall/will be done 一般将来时

　　例Hundreds of jobs will be lost if the factory closes.

　　8） should/would be done 过去将来时

　　例The news would be sent to the soldier's mother as soon as it arrived.

　　9） shall/will have been done 将来完成时（少用）

　　例The project will have been completed before July.