A examination of the picture immediately reveals that the source of its mood is the air pollution resulting from a huge number of automobiles spread around its surface.

仔细观察这幅图就会发现其郁闷来自于空气污染，这是由于其表面上有着无数车辆在行驶。

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Jackson is using a section of the clean Air Act, the New source Performance Standards, to clean up existing sources of carbon pollution.

Jackson在利用《清洁空气法案》的其中一章——“新排放源绩效标准”来清理现有的碳排放源。

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On the negative side, automobiles are the main source of air pollution in the world which creates the so-called green-house effect.

而消极的一面是，汽车是世界上污染的主要来源，产生了所谓的温室效应。

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Janice Nolen, national policy adviser at the American Lung Association, says that rather than dealing with the harmful effects of air pollution, the focus should be on tackling the problem at source.

CNN: Smog-eating tiles gobble up air pollution