People tend to work hard at this stage of life.

人在这个人生阶段往往发奋努力。

《牛津词典》

Work hard at school!

在学校努力学习！

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Work hard at your lessons.

努力学功课。

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The Great Recession gave some mothers no choice but to work, as job cuts hit hard at men.

VOA: special.2010.04.23

I mean, they have no idea how hard we work, and look at this gigantic split infinitive, to dramatically help.

他们不知道我们有多么努力地工作，注意到这之间的巨大鸿沟，会有很大的帮助。

麻省理工公开课 - 固态化学导论课程节选

And so, just a lot of hard work and a lot of time at the golf course in the summer.

所以，夏天时，一直努力练习，在高尔夫球场花了不少时间。

高尔夫俱乐部的回忆 - SpeakingMax英语口语达人

In the U.S. Nardelli has been hard at work reversing years of underinvestment in aging stores.

FORBES: Hammered

At the same time, the U.N. must work hard at selling its peace plan to neighboring nations, so they will rein in their proxies in Afghanistan.

CNN: A Workable Plan

While Corbat has mostly stayed out of the spotlight since taking over for Pandit Oct. 16, he has clearly been hard at work.

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