We have realized she is expecting is just an opportunity to test her ability.
A. that
B. which
C. what
D. where
网友回答
A. that
B. which
(答案→)C. what
D. where
解析：C 考察名词性从句。Realize后面跟宾语从句， she is expecting在宾语从句中做主语，expecting后面缺少宾语，且指内容。故使用what作为引导词。故C正确。