The level of carbon dioxide in the atmosphere is measured in parts per million (PPM).

大气层里二氧化碳含量的测量单位是ppm，即一百万体积的空气中所含二氧化碳的体积数。

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A normal amount of CO in your blood is extremely low — zero to eight parts per million.

血液中CO普通含量相当低——零至百万分之八。

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Want concentration of CO2 in atmosphere lowered from 380 to 350 parts per million.

希望将大气中二氧化碳含量由百万分之380降低到百万分之350。

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Carbon monoxide is measured in parts per million in a normal atmosphere.

VOA: special.2010.02.02

The team found levels of lead as high as thirty-two thousand parts per million in tests on some paint samples from Ecuador.

VOA: special.2009.08.31

Breathing in two hundred parts per million of carbon monoxide will cause the first signs of poisoning.

VOA: special.2011.01.25

Given that those molecules are absorbed at different wavelengths, the machine can measure the amount of absorption and calculate the concentration of greenhouse gases in parts per million.

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The trajectory for our carbon pollution predicts that 688 parts per million will be in the atmosphere in the year 2095 and 1, 097 parts per million in the year 2195.

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Carbon-dioxide levels in the atmosphere have grown 38 percent to approximately 389 parts per million today from 280 parts per million in 1850, the pre-industrial benchmark for climate change.

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