Note：PPM means part per million, usually a measure of quality.

注：PPM是百万分之一件的缩写，通常是质量的一种指标。

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The process USES small amounts of the naturally occurring mineral to increase concentrations to no more than one part per million typically.

这一过程应用了少量的自然出现的矿物质去增加浓度，不超过百万分之一。

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The agency said it had determined that levels of melamine or one of its related compounds, alone, below 1 part per million in infant formula were not a concern.

这个机构说，它已作出结论，婴儿配方食品中含有低于百万分之一的三聚氰胺或其中任何一种与其相关的化合物无需担心。

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Eleven dollars per part at 12.5 million cars and trucks came to a total cost of $137 million to improve the safety.

给1250万辆轿车和卡车配上11美元的隔板,提高安全性，共需花费一亿三千七百万美元。

耶鲁公开课 - 公正课程节选

So for every part per million (ppm) increase, a little less warming is generated.

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Of course, there are always the ubiquitous environmentalists for whom even one part per million of oil anywhere is unacceptable.

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"What we found for our 124 sharks that we sampled was that about one-third of them came in with mercury levels that were over the Food and Drug Administration's action level of one part per million, " said Hueter.

CNN: Beware of shark meat, FDA warns