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- I've been hard at it all the morning. 我一上午都在卖力地干。
- He's been hard at it for several months now,and nothing we do can restrain him. 他酗酒已好几个月，我们怎么也制止不了他。
- And,although scientists at Livermore and elsewhere were hard at work at it,so far as I know we have never developed a true "neutron bomb",that is,a "zero-fission fusion" weapon. 尽管Livermore还有其它一些机构的科学家们在这方面已经进行了大量研究工作，但就我所知，现在我们仍没有开发出真正的“中子弹”，即一种“完全的核分裂聚变”武器。
- My English is very poor, so I will work hard at it. 我的英语水平很差,所以我得努力学习它。
- I've been going hard at it all day. I'm exhausted. 我一整天辛苦地工作,感到很疲惫了。
- I studied art and worked hard at it. 我学艺术,而且很用功。
- You must have worked very hard at it. 你一定花了很大劲。
- The policemen were already hard at it when we reached the scene of the accident. 当我们到达肇事地点时，警察们已经在哪里忙开了。
- Not all students be good at studying English, but if we work hard at it; we will do better and better in it. 不是所有学生擅长学习英语,但如果我们努力学习,成绩会越来越好。
- The squire was hard at work at Bristol. 乡绅在布里斯托尔热衷于他的工作。
- I want to work hard at it to be able to speak Spanish fluently as "rapido" as possible. 每天跟自己说，“你只要相信自己，没什么打不了！”
- It was hard work, but everybody went at it with a will. 劳动很艰苦, 可大家干劲十足。
- Times were hard at the end of the war. 战争后期生活很艰苦。
- Some are hard at work and some are slack in work. 有的勤奋工作, 有的则消极怠工。
- When I left they were all still hard at it(= working hard). 我离开的时候他们都还在努力工作。
- You can make great progress in your English if you work hard at it. 如果你努力学习,你就会在英语方面取得很大进步。
- You can make rapid progress in your English if you work hard at it. 如果你努力学习,你的英语会迅速取得进步。
- Whatever you do, work hard at it and don't try to dodge the column. 无论做什么事, 都要努力去做, 别偷懒。
- they were hard at it with brooms and mops. 他们忙着用扫帚和拖把打扫卫生。
- If the ink sinks in it'll be hard to remove it. 如果墨水渗入，要除去就很困难。
