The body holds onto a small percentage of oxygen with each breath, and the rest is exhaled.

每一次呼吸机体都只保留一小部分氧气，其他的都被呼出去了。

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The smaller the particle size was, the higher percentage of oxygen was for the same composition of raw materials.

对于相同原料制取的锆粉，粒度越细，其含氧量越高。

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The bulk fraction is a mixture of methane, carbon dioxide, hydrogen, nitrogen and oxygen. These are measured in terms of percentage by volume.

主要成分是甲烷，二氧化碳，氢气，氮气和氧气的混合气体，这些成分的含量一般用所占填埋气的体积比来表示。

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By Sunday, she had improved significantly to 33% -- just 12 percentage points shy of 21%, the level of oxygen in air around us.

CNN: STORY HIGHLIGHTS