On most commercial planes, at least half of the air comes from outside the aircraft and passes through a high-efficiency particulate air, or HEPA, filter which removes contaminants

在多数商用飞机上，至少有一半空气是来自于飞机外部，而且都经过了一种高效空气净化装置的过滤。

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On most commercial planes, at least half of the air comes from outside the aircraft and passes through a high-efficiency particulate air, or HEPA, filter which removes contaminants.

大部分的商业飞机上，至少有一半的空气来自飞机外面，并经过高…也叫HEPA，过滤装置。可以去除污染。

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