我们需要不会污染环境的更清洁燃料。

We need cleaner fuels that don't ___pollute the environment.

它们大多数不污染环境，也不会造成道路拥堵。

Most of them don't ___pollute the environment, and they don't create traffic jams on the roads.

这家工厂因化学废物污染河流而被罚款。

The factory was fined for ___polluting the river with chemical waste.