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《清洁空气法案》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。

youdao

All new cars, too, are built so that they can only take unleaded gas.

同时，所有的新型车都只能加无铅汽油。

youdao

In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation world-wide has decreased significantly.

在过去的20年里《空气洁净法案》要求在美国只能使用无铅汽油，因此世界范围内的铅沉积有了显著下降。

youdao

The switch to Sunoco Green E15, the official fuel of NASCAR and a renewable, low-carbon power source, reduced greenhouse gas emissions by 20% compared with unleaded gas.

FORBES: NASCAR Green Is Really Purple