问题补充:
It is that I can still remember was discussed at the meeting.
A. sure; when
B. sure; what
C. certain; when
D. certain; what
答案:
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。