It is announced that……. 据宣布
　　it is (well) known that……. 众所周知
　　It has been decided that……. 已经决定
　　It is supposed that……. 人们认为
　　It is suggested that……. 有人建议
　　It must be remembered that……. 务必记住
　　It is taken for granted that……. 被视为当然
　　(五)主动句变被动句的注意事项
　　一是时态不能改变;二是变为被动语态后，谓语动词要和被动语态的主语在人称、数上保持一致。还要作如下变动：把主动语态的宾语变为被动语态的主语;主动语态的主语放在by的后面，组成介词短语，再把这个介词短语放在被动语态的谓语动词之后。在动作的执行者无须说明或不必要强调时，by短语可以省略。例如：
　　They will open a new supermarket there soon. 他们很快将在那里开办个新超市。
　　A new supermarket will be opened there soon. 一个新超市不久将在那里开办。
　　The doctor gave two lectures in English. 那位医生用英语讲了两次课。
　　Two lectures were given by the doctor in English. 由那位医生用英语讲了两次课。
　　Somebody has warned us to be careful of rats. 有人警告我们要当心老鼠。
　　We have been warned to be careful of rats. 我们受到警告，要当心老鼠。
　　如果主动语态有两个宾语(直接宾语和间接宾语)，变为被动语态时，可将其中任何一个宾语变为主语，另一个不变。但较常见的是将间接宾语变为被动语态的主语。
　　The reporters asked the president some questions. 记者们问了总统一些问题。
　　The president was asked some questions by the reporters. ( 变间接宾语为主语)
　　Some questions were asked the president by the reporters. (变直接宾语为主语)
　　We have given him a job. 我们已给了他一个工作。
　　He has been given a job. (变间接宾语为主语)
　　A job has been given (to) him. (变直接宾语为主语)
　　(六)含有情态动词的被动语态
　　句中含有情态动词时，其被动语态的结构是：情态动词+be+过去分词：
　　The timetable can be changed any time. 时间表随时可以改变。
　　This book may not be taken out of the reading room. 这本书不允许带出阅览室。
　　This dictionary must be taken good care of. 这本词典必须保管好。
　　(七)不能用于被动语态的动词
　　1、不及物动词不能用于被动语态，因为它们没有宾语。
　　2、表示状态而不是动作的及物动词，如 break out, belong to, cost, deserve, fit, have ( 有、使)，hold (盛下、装下)，lack, resemble, suit, take part in, take place, want, wish等动词不能变为被动语态。例如：
　　Everybody wanted Doris to be the manager. 大家都想让多里斯来当经理.
　　We like everybody to say what they think. 我们喜欢让人人都说出他们的看法。
　　Do you wish me to stay? 你希望我留下吗?
　　Will you help me (to) do the work? 你可以帮助我做干活吗?
　　The war broke out in 1937. 战争爆发在1937年。
　　This car belongs to me. 这车是属于我的。
　　He has a good job. 他有个好工作。(不说A good job is had by him.)
　　They have a large house. 他们有所大房子。
　　I’ll have him come early. 我要让他早来。