问题补充:
is known to us all is the sun is bigger than the earth.
A It; that B What ; that C What ; how D That; that
答案:
解析:考查主语从句和表语从句。本题第一空what is known to us all是一个主语从句,what引导起主语从句并在句中做主语。第二空that引导的是表语从句,that在句中不充当任何成分,只起引导和连接作用。句意:众所周知的事情是太阳比地球要更大。故B正确。