为控制氮污染，无论过去还是现在，我们都做出了许多尝试。但我们认为最大的挑战还是将现行的政策领域联系起来使它们共同发挥作用。

There have been and still are many attempts to control nitrogen but we believe the big challenge is to link existing policy areas and make them work together.

youdao

为控制氮污染，无论过去还是现在，我们都做出了许多尝试。但我们认为最大的挑战还是将现行的政策领域联系起来使它们共同发挥作用。

There have been and still are many attempts to control nitrogen but we believe the big challenge is to link existing policy areas and make them work together.

youdao