hard at work

基本解释

Some are hard at work and some are slack in work.
有的勤奋工作，有的则消极怠工。
《新英汉大辞典》
So while participants in the program do absolutely nothing, their computers are hard at work, saving lives one calculation at a time.
当参与者停止使用计算机的时候，其实计算机正在努力的工作，在任何一个时刻都在积极地计算着。
But if rest is the goal, why does our brain remain hard at work?
但是如果目的仅是休息，为什么我们的大脑仍然保持辛苦的工作状态呢？

But he is hard at work. He and his team currently are trying to make algae that can change carbon dioxide back into fossil fuel.
So, now that you're fully immersed in CS50 it's quite understandable 0 if you want people to know that you're in CS50 and so the teaching fellas have been hard at work putting together this year's line of apparel which includes sweatshirts, CS50 T-shirts and the like.
现在你已经完全沉浸,于CS50的学习，这完全可以理解,你很想让大家知道你在CS50学习0,我们的助教们已经,将今年的服饰收集在了一起,其中包括运动衫，CS50，T恤等等。
哈佛公开课 - 计算机科学课程节选
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

Some very smart people are hard at work at figuring out how to do so.
FORBES: Everything Economics Turns On A Trifle