单选题
1._______ is known to all,China will be an _______ powerful country in 20 or 30 years' time.
A.That;advancing
B.This;advanced
C.As;advanced
D.It;advancing
正确答案:C
答案解析:as可以用来引导一个非限制性定语从句,通常无明显的先行词。as指代的是主句陈述的内容。而as引导的从句既可以放于句首,也可以放于句末或句中。