问题描述：
As long as there have been mice,people have sought a better mousetrap.这句话不懂.
As long as there have been mice,people have sought a better mousetrap.这句话为什么用现在完成时?
As long as there have been mice,people have sought a better mousetrap.这句话为什么用现在完成时?
问题解答：
我来补答展开全文阅读