is known to us all is that the 2008 Olympic Games will take place in Beijing.A.I

_________ is known to us all is that the 2008 Olympic Games will take place in Beijing.

A.It

B.What

C.As

D.Which

试题答案

B

解析：

本题考查复合句。句意为：众所周知，2008年奥运会在北京举行。What引导主语从句的同时又作主语从句的主语，具有双重功能；

It作形式主语时必须把后面的is去掉，as作为关系代词时也要把后面的is去掉并改为逗号，which不能放在句首。因此答案选B。本题干扰选项为A、C两项，难度较大。