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来源：雅诚德英语网
In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation worldwide has decreased significantly.
在《清洁空气法》强制要求美国使用无铅气体的二十年里，铅在世界范围内的累积量显著下降。
In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation worldwide has decreased significantly.
在《清洁空气法》强制要求美国使用无铅气体的二十年里，铅在世界范围内的累积量显著下降。