1、It + be + 名词 + that从句：It is a fact that 事实是。

It is an honour that 非常荣幸。

It is common knowledge that …是常识。

It is a pity that 遗憾…… 。

2、It + be + 动词的过去分词+ that从句。

It is said that 据说。

It is reported that 据报道。

It has been proved that 已经证明。

It is believed that … 人们认。

It is supposed that… 据猜测，

3、It + 不及物动词（vi） + that 从句。

It seems that 似乎。

It happened that 碰巧。

It appears that 似乎。

4、It is natural that… 很自然…。

It is strange that… 奇怪的是… 。