问题补充:
is known to everybody, Taiwan is a part of China. We must unify it.
A. It
B. As
C. Which
D. What
答案:
A. It
(答案→)B. As
C. Which
D. What
解析:先行词是Taiwan is a part of China整个主句,一般由as或which引导定语从句,但which引导的定语从句只能放在主句之后,另外,as有“正如”之意,而which没有,所以用as。顺便说说,原句改为:It is known to everybody that Taiwan is…= What is known to everybody is that Taiwan is…