are shut.

　　在你离开实验室之前，要确保电源被切断，窗户被关好。

　　(2)一般过去时被动语态的构成：was/were＋done

　　The foreign guests were given a warm welcome by the children.孩子们热烈地欢迎外宾。

　　(3)一般将来时被动语态的构成：shall/will＋be＋done

　　More space explorations will be made in the future by the Chinese people.

　　中国人民在将来将进行更多的太空探索。

　　(4)现在进行时被动语态的构成：am/is/are＋being＋done

　　They are living with their parents for the moment because their own house is being rebuilt.

　　他们现在暂时和父母一起居住，因为他们自己的房子正在重建。

　　(5)过去进行时被动语态的构成：was/were＋ being＋done

　　After school we went to the reading­room to do some reading，only to be told that it was being decorated.放学后，我们去阅览室看书，结果却被告知阅览室正在装修。

　　(6)现在完成时被动语态的构成：has/have been＋done

　　Li Hua has been elected monitor of our class to take the place of Ma Li.

　　李华已取代马丽，被选为我班班长。

　　(7)过去完成时被动语态的构成：had been＋done

　　When we got on the spot of the accident，we were told that the injured had been sent to the nearest hospital.当我们到达事故现场时，我们被告知伤员已经被送往最近的医院。

　　(8)将来完成时被动语态的构成：will/shall＋have been＋done

　　On her next birthday，Ann will have been married for twenty years.

　　到下一次过生日的时候，安结婚就要满二十年了。

　　(9)含有情态动词的被动语态的构成：情态动词＋be＋done

　　The boy feels very hot on the forehead，so he must be sent to hospital at once.

　　这个男孩的额头摸起来很热，所以必须被立刻送往医院。

[即时训练1]　用所给词的被动语态填空