1、It Is known to us that /to do是独立句,其中it 是形式主语,真正主语是后面that 从句或to do动词不定式,举例如下;
It Is known to us that the earth revolves around the sun.
众所周知,地球围绕太阳公转。
2、as is known to us 是从句,非限定定语从句前置形成,举例如下;
the earth revolves around the sun,which Is known to us.
地球围绕太阳公转,这个我们都知道。
当非限定定语从句which Is known to us前置到句首,which必须换成as,转换成as is known to us,所以形成;as is known to us, the earth revolves around the sun.
3、as is known to us不能作为独立句,后面必须接主句;
As is known to us, the chinese are a industrious and gallant nation.
众所周知,中国人民是勤劳勇敢的民族。
1,It is known to us all中的It为形式宾语,因此这种结构后必须接一个主语从句来作真正的主语.
这个主语从句可以是that或wh-类连词引导的从句.即:
It is known to us all+that/what/when/where/how从句.
2,as is known to us all是由as引导的定语从句,
as指代后面或前面的整个主句,因此as is known to us all结构可放句首,也可放句中或句末,
但一定要用逗号与主句隔开.
3,what is known to us all是一个名词性从句,常用来作主语从句,用于这个结构中:
What is known to us all is that....
例如:
It is known to us all that he will visit our school tomorrow .
=As is known to us all , he will visit our school tomorrow .
=What is known to us all is that he will visit our school tomorrow .
As is known to us all, the earth goes round the sun!
=It is known to us all that the earth goes round the sun!
=What is known to us all is that the earth goes round the sun!
It is known to us all when the meeting will be held .
=It is known to us all where the meeting will be held .
=It is known to us all why you didn't come to school yesterday.