氮中二氧化碳和空气中甲烷气体标准物质属于标准混合气。

The two gaseous Reference Materials, Carbon dioxide in nitrogen and methane in air, belong to standard mixed gases.

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氮中二氧化碳和空气中甲烷气体标准物质属于标准混合气。

The two gaseous Reference Materials, Carbon dioxide in nitrogen and methane in air, belong to standard mixed gases.

youdao