英语高手进 ！！

be said/be supposed/be believed/be thought/be known/be reported + to do(要做)/to be doing（正在做）/ to have done （做完了）
拓展：类似的句式还有
It's hoped that…　人们希望……
It's thought that…　有人认为……
It's ordered that…　已下令……
It's supposed that…　据推测……
It's well known that…　众所周知……
It's pointed out that…　需要指出的是……
It must be admitted that…　必须承认的是……
注意：此种句型it为形式主语，真正主语为that引导的从句，且that不可省略。
该句型也是高考的测试点：如：
1．　Robert is said ______ abroad, but I don't know what country he studied in (NMET 1999)
A．to have studied　B．to study C．to be studying　　 D．to have been studying
解析：动词不定式的完成式表示过去发生的动作，即study动作发生say之前，从后面studied所用过去时态可知这一事早已发生。所以须用to have done形式。表明："据说罗伯特过去曾经在某个国家学习过，但我不知道是在哪个国家"。答案为A。
In fact, the London Stock Exchange is believed to have started from these coffeehouses. (必修1，P18)
It is/was said/reported/believed/thought/known/ considered …＋that－clause 意为"据称/据说/据报道/大家认为/ 众所周之/ 人们认为……"，这一句型中it 是形式主语，后面的that 从句是真正的主语。
以上这种句型可以转换成下面两种句型：
1. People say/believe/think … that clause 和
sb be said/reported/thought/believed to do/have done sth…

It is reported that Cheng Yifei died several days ago.
The news reports that Cheng Yifei died several days ago.
Cheng Yifei is reported to have died several days ago.
据报道，陈逸飞于几天前去世。
It is thought that FIR is one of the best pop groups in China.
People think that FIR is one of the best pop groups in China.
FIR is thought to be one of the best pop groups in China.
人们认为FIR乐队是中国最流行乐队之一。
It is believed that Henry stole the car.
People believe that Henry stole the car.
Henry is believed to have stolen the car. 人们相信小汽车是亨利偷的。
顺便 把据说 这种词的写法也告诉你，记得作文的时候用上去哈