问题
选择题
________ is known to everybody，the moon travels around the earth once every month.
A．It
B．As
C．That
D．What
答案
答案：B
解析 本题考查as引导的非限制性定语从句。as作“正如……”解时，引导的非限制性定语从句来修饰整个句子，可前指或后指，此处为后指。当as在从句中作主语时，常用于下列短语：as is known，as is said，as is reported，as is announced等。