Air is made up of three main types of gases: oxygen, carbon dioxide, and nitrogen.

空气是成立的三种主要类型的气体：氧，二氧化碳和氮。

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Air is made up of three main types of gases: oxygen, carbon dioxide, and nitrogen.

空气是成立的三种主要类型的气体：氧，二氧化碳和氮。

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