______ is known to all, the earth travels round the sun once every year．
A．That B．As C．What D．It
______ is known to all, the earth travels round the sun once every year．
A．That B．As C．What D．It
B
本题考查as引导的定语从句。当as引导定语从句、修饰整个主句时，可以放在句首、句中或者句尾。注意：be known to …是一个固定词组，意思是“为 … 所熟知”；如果本题用D项，则应改为“It is known to all that the earth … ”。