is known to us a11 is that the Diaoyu islands have been part of our Chinese territory since ancient times.
A. As
B. Which
C. It
D. What
网友回答
A. As
B. Which
C. It
(答案→)D. What
解析：句意：我们大家都知道的是钓鱼岛历来都属于我们中国的固有领土。
此题为主语从句，what引导主语从句时，既做主语从句的主语，又做主语从句的引导词。
考点:考察名词性从句引导词的用法