You don't need a light switch or a light bulb or an iPhone app to turn something on or off.

你不需要电灯开关、灯泡或苹果手机应用程序来打开或关闭某些东西。

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These reactions influence how our genetic code is expressed: how each gene is strengthened or weakened, even turned on or off, to build our bones, brains and all the other parts of our bodies.

这些反应影响着我们的遗传密码的表现方式：每个基因是如何被加强或削弱，甚至其作用机制是如何被打开或关闭，从而构成我们的骨骼、大脑以及身体的其他部位的。

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Students should avoid any immodest behaviour, on or off campus.

学生们应该在校园内外都避免有任何傲慢无礼的行为。

《柯林斯英汉双解大词典》

This was often dangerous, because guards on the train would throw the men off or arrest them.

VOA: special.2010.06.13

Well, if you're implementing a computer that needs to represent information now all you need is something like electricity which can be on or off, on or off.

好吧，如果你正用一个电脑,来表现表达传递信息的功能,你就需要,像电开关一样的物体。

哈佛公开课 - 计算机科学课程节选

But at the end of the day, and here's why we just went with binary and not decimal years ago, when you have one implement a computer with a physical device, it's actually really easy to represent the notion of on or off.

但是最终，之前我们采用二进制,而不是十进制，主要是因为当我们用一台实体机器运行计算机时，这实际上很容易用开或者关的概念来表示。

哈佛公开课 - 计算机科学课程节选

Each contact can be independently controlled, on or off, with various levels of electricity.

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And there's no way for others to tell whether that camera is on or off.

WSJ: Google Glass: An Etiquette Guide

The cells can then be turned on or off with pulses of blue and yellow light.

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