work hard

问题描述:

work hard

致力于/努力 ...
He works hard at Math."他努力学习数学"

努力工作于。。。

努力致力于

致力于

对什么很努力
致力于 [简明汉英词典]
apply oneself to
bend oneself to
commit oneself to
hammer at
take up with

工作艰苦