第1个回答 2009-11-17
How come I didn't think of it!
第2个回答 2009-11-09
Why didn't I think of that?本回答被提问者采纳
第3个回答 2009-11-09
How i didn't think of it?
第4个回答 2009-11-09
I agree with the third floor,I think it's the standard answer for your question !呵呵
第5个回答 2009-11-09
why haven't I thought of it?