the population of China is the largest in the world.A. It is known thatB. As is well kn

问题补充：

, the population of China is the largest in the world.

A. It is known that

B. As is well known

C. Which is well known

D. We all know that

答案：

A. It is known that

(答案→)B. As is well known

C. Which is well known

D. We all know that

解析：众所周知，中国的人口在世界上最多。 as 引导的定语从句才能位于句首。