被动语态之使用场合

　　⑴在不知道动作的执行者是谁时。如：You are wanted on the phone. 有你的电话。(不知道是谁请你接电话) Everything has been taken away. 一切都被拿走了。(不知道是谁拿走的) These books are written for children. 这些书是为孩子们写的。(谁写的不知道)
　　⑵当动作的执行者是泛指或不言自明时。如：Not a book in the library has been taken away. 没有一本书在图书馆里被人带走。(泛指任何人) China was liberated in 1949. 1949年中国解放。(不言而喻是中国共产党解放的)
　　⑶虽然可以说出动作的执行者，但动作的承受者是谈话中心或特别需要强调时。如：My watch has been repaired. 我的表修好了。(表修好了是谈话的主旨，是谁修好不必提及) At last an agreement was arrived at. 终于达成了一项协议。(重要的是达成协议) She is liked by everyone in our class. 班里每个人都喜欢她。(强调她)
　　⑷出于委婉、礼貌而避免提及自己或对方时。如：Enough has been said on this question. 关于这个问题已经谈得不少了。(大家不要再说了) You are wished to do it more carefully.希望你认真一点儿做。(谁希望，不愿或不便说出来)
⑸当人不是动作的执行者时。如：We are all shocked by the news of his sudden death. 他的突然去世使我们大家都感到震惊。The house has been washed away by the flood.房子已被洪