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：“我肯定记得大会上讨论过的事。”sure的主语必须是人，certain的主语可以是人和物，第二空从句缺主语所以用what，答案D。