--- An ant has two stomachs --- one for itself, one for others.
--- Really? Quite interesting. I anything about it.
A. don’t know
B. have known
C. haven’t known
D. didn’t know
网友回答
A. don’t know
B. have known
C. haven’t known
(答案→)D. didn’t know
解析：考查动词的时态。根据句子我不知道蚂蚁有两个胃是在你告诉我之前，现在已经知道了，是过去不知道，所以用一般过去时态。选D。