The process uses a closed system to keep hair and dirt out of the milk.

VOA: special.2010.07.20

The system can be an open system, or it can be a closed system, or it can be isolated.

系统可以是开系，可以是闭系，或是孤立系。

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We don't say anything about implicitly here, we're talking about a closed system, so there's no mass leaving the system.

我们不讨论,这是隐含条件，因为我们讨论的是孤立系统，因此系统没有物质流失。

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It's insulated. It's a closed system. In fact, it's an isolated system. There's no energy or matter that can go through that boundary.

系统指的，是盒子里的东西,它是封闭孤立的。

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So a closed system would be, for instance, a glass of ice water with an ice cube in it, with the lid on top.

因此闭系可以是，比如说，一杯放了,一个冰块的冰水，顶上加了盖子。

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It's a closed system, so the number moles doesn't change.

这是一个封闭系统，因此摩尔量不会改变。

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