Question

____is well-known to all, the great changes have taken place in China.

A. It
B. that
C. As
D. Which

Answer 1

答案C
考查定语从句。此处有逗号隔开，此句子不是形式主语的句式，前面的句子修饰后面的句子构成一个非限制性定语从句，as可以放于句首，意思“这一点”来指代后句。