定语从句改错:This is the most difficult maths problem which I have done.

问题描述:

定语从句改错:This is the most difficult maths problem which I have done.

这么简单 还要问 which----that

which ------改写成that就是了,因为形容词,序数词和顺序词(next , last)被定语从句修饰是,我们用that,不要which.