Volunteers were told to think about yawning while they breathed either normal air, pure oxygen, or an air mixture with an above-normal level of carbon dioxide.

当志愿者在正常的空气中、纯氧的环境下，或者混有超过正常的二氧化碳含量的空气中呼吸时，他们被要求要想着打哈欠。

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Volunteers were told to think about yawning, while they breathed either normal air, pure oxygen, or an air mixture with an above-normal level of carbon dioxide.

当志愿者在正常的空气中、纯氧的环境下，或者混有超过正常的二氧化碳含量的空气中呼吸时，他们被要求要想着打哈欠。

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Powdered material may form explosive dust-air mixture.

粉状材料可形成爆炸性粉尘空气混合物。

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Get the fuel-air mixture a few knob twists wrong from the LOP side, and you can blow up your engine.

FORBES: Institutional Stupidity, III

The engines increase airflow, creating a more complete burning of the air-fuel mixture--and a more powerful vehicle.

FORBES: Magazine Article

This is possible because with the lasers, the location of the ignition can be in the center of the air-fuel mixture, rather than just the portion closest to it.

FORBES: Replacing Spark Plugs With Lasers For A More Fuel-Efficient Car