could和couldn't的不同
could和couldn't的不同
could和 must和 couldn't 的区别和用法?
could't与couldn't的区别?
求两组英语句型的解释could have done 和 couldn't have doneshould have do
didn't 和couldn't的区别,
couldn`t的意思和时态
couldn t和
用can、can't、could、couldn't写一篇关于自己的短文 不少于60词
用can,can't,could和couldn't写一篇关于简,迈克,玛利亚的英语作文,他们会做什么,不会做什么.
can't和couldn't
couldn't和shouldn't的区别,急要
can have done和could have done有无区别?can't have done和couldn't h