My brother is good __English ,and I do well __Maths.We all work hard __them.

题目

My brother is good __English ,and I do well __Maths.We all work hard __them.
横线上为什么分别填上 at,in,at

答案

都是固定搭配呀
be good at 与do well in 同义‘擅长于……,在……方面做得好’
work hard at ...努力学习……