it be过去分词 that

it is hoped that希望 it is asked that要求 it is heard that听说

你好.你说的“it +be +过去分词+从句”是主语从句.原先,是由宾语从句变来的:They say that he enjoys classic music(宾语从句)-----------(主语从句):It is said that

那个

1.It is said that 据说(=people say 即大家都这么说)that 后面接一个从句,that 可省略.例: It is said (that) he is only 13 years old.据说他才13岁. =He is said to be only 13

有的,比如 it is said据说 it is reported that据报道 it is believed that 人们认为 这几个是被动,过去分词,因为,逻辑主语是省略了by sb 而,it is important for sb to do sth 的逻辑主语是 for sb,就是人,人自己做事,是主动的

It is said that President Obama will visit your school next month.It is required that you should finish you homework before next class.

It was greatful that you have helped me. It would be a problem that the world is becoming hotter and hotter. It is said that President Hu will come to ** tomorrow. It is reported that there is a hurricane on the way. It is me that answer your quetion. It is BeiJing that held the 2008 Olympic Games.

It is said that president will come to our school tomorrow.

你这里指的是英语中的虚拟语气现象吧.这应该是你们老师或者一些辅导书这么归纳的 坚持类的过去分词常有:insisted;命令类的有:ordered, commanded;建议类的有:suggested, proposed, recommended;要求类的有:requested, desired, required, asked, demanded

不能,that引导的是主语从句,it在句中是形式主语.that做宾语时可以省.