Sulfur dioxide, a major contributor to acid rain, is an especially serious pollutant because it diminishes the respiratory system's ability to deal with all other pollutants.

二氧化硫是酸雨的主要成因之一，它是一种特别严重的污染物，因为它会降低呼吸系统处理其他污染物的能力。

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Combined with water vapor, sulfur dioxide forms sulfate aerosols, which can spread around the globe, blocking solar radiation and chilling the air before becoming acid rain and snow.

二氧化硫跟水蒸气结合形成硫酸盐气溶胶，这种气溶胶可以遍布全球，在变成酸雨和酸雪之前阻隔太阳辐射，降低气温。

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Vegetation in the surrounding area has been destroyed by acid rain due to high sulfur dioxide emissions.

二氧化硫的高排放引起的酸雨使得周围的植物遭到大面积破坏。

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Ferretti, vice president at the Chicago Climate Exchange, extolled emissions trading, noting that the practice had helped bring sulfur dioxide and acid rain under control much less expensively than traditional command-and-control regulation.

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Back then, the concern was sulfur dioxide, the culprit behind acid rain.

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The limit is now set at about half of the amount of sulfur (the leading cause of acid rain) released in 1980.

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