重点讲解：
1. round up
使聚拢；使聚集；
eg. He had sought work as a cowboy, rounding up cattle.
他找了一份放牛的差事，负责把牛赶到一起。
eg. I round up a few friends for a party.
我找了几个朋友聚了聚。
2. keep in check
控制；
eg. He's found someone with a bit of fight to keep him in check.
他发现有个厉害的主儿能镇住他了。
eg. The prisoners must be kept in check.
囚犯们必须严加管束。
3. gear up
为…作准备；为…作好了准备；
eg. I am now in high school, it's time gear up for study.
现在我是一名高中生了，该是努力学习的时候了。
eg. The ban was lifted last month, but aid agencies say it takes time to gear up.
此禁令已于上月取缔，但是援助机构称需要时间进行准备。
4. back down
放弃（主张、要求、承诺等）；打退堂鼓；
eg. He had to back down on plans to backdate the tax changes.
他不得不放弃追溯税收调整的计划。
eg. After being confronted with our evidence, the other side had to back down.
面对我们的证据，另一方不得不退让。
5. room for
机会；余地；可能性；
eg. The intensity of the work left little room for personal grief or anxiety.
高强度的工作使人几乎没空去悲伤或者忧虑。
eg. There's lots of room to express yourself creatively.
有很多让你展现创意的机会。