Liu Xiang’s breaking the world record was an exciting moment, all of us will never forget.
A. that
B. one
C. it
D. what
网友回答
A. that
(答案→)B. one
C. it
D. what
解析：考查定语从句。代词one是moment的同位语，all of us will never forget是省略了关系代词that 的定语从句；非限制性定语从句不用that引导，所以A项不对。