He is the best ____English in our class.A at B in C for D to

问题描述:

He is the best ____English in our class.A at B in C for D to
He is the best ____English in our class.
A at B in C for D to
应该有个固定语法be good at sth.

He is the best __B___English in our class.那为什么不能选A呢?它在英语方面学得好。
所以用in.be good at sth固定语法为什么不能用?在什么方面,应该用:in.