（英语改错） you must work hard on English and never give up learning it.on为什么要改为at.
问题描述：
（英语改错） you must work hard on English and never give up learning it.on为什么要改为at.
答
固定搭配
work hard at…在……方面努力工作
work hard at sth努力学习
work hard at math在数学上努力
work hard at sth.在…努力
work hard (at)勤奋工作
We must work hard at English.