pollute

我们需要一种不会污染环境的燃料。

We need a fuel that won't ___pollute the environment.

工厂经常用化学废物污染河流。

Factories often ___pollute the river with chemical waste.

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.