It is that I can still remember was discussed at the meeting.
A. sure; when
B. sure; what
C. certain; when
D. certain; what
网友回答
A. sure; when
B. sure; what
C. certain; when
(答案→)D. certain; what
解析：句意：我肯定记得大会上讨论过的事。sure的主语必须是人，排除AB，certain的主语可以是人和物，第二空用what，引导宾语从句，因为从句缺主语所以用what，答案D。