1. zero in on

　　Meaning: If you zero in on something, you focus your attention on it.

　　中文解析：瞄准，对准…;对…集中火力、注意力

　　If you're reporting on an issue rather than an event, first get the reader interested by zeroing in onthe main players and their conflict.

　　如果你在就某争议问题做报告而非某事件，那么首先你要让读者注意到主角和他们之间的冲突。

　　I like the way our lecturer zeroes in on the central issues without spending too much time on all that boring background information.

　　我喜欢这种授课风格，授课者直接集中火力在主要事件上而非花过多时间在无聊的背景信息上。

　　2. zero tolerance

　　Meaning: If something is given zero tolerance, it won't be accepted even once.

　　中文解析：零容忍，一次都不允许。

　　Because of the school's zero-tolerance policy, our boy was expelled for smoking just one cigarette.

　　由于学校采取零容忍政策，所以学校男生仅仅因为吸了一根烟就被开除了。

　　3. zero-sum game

　　Meaning: A zero-sum game is a situation in which any gain by one side or person is at the expense of a loss to another side or person involved in the situation.

　　中文解析：零和博弈又称零和游戏 (zero-sum game)，与非零和博弈相对，是博弈论的一个概念，属非合作博弈，指参与博弈的各方，在严格竞争下，一方的收益必然意味着另一方的损失，博弈各方的收益和损失相加总和永远为“零”。双方不存在合作的可能。

　　The stock market has become a giant zero-sum game in which one investor gains what another investor loses.

　　股票市场已经成了一个巨大的零和博弈游戏，在股票市场中一个投资者赚到的同时就会有另一个投资者输钱。

　　In a zero-sun game, if you add the total gains of the participants and the total losses of the participants, the sum will always be zero.

　　在零和游戏中，如果你把所有参与者赚到的和输掉的加在一起，总和永远是零。