They keep our air clean, reduce noise pollution, improve water quality and provide food and building materials.

他们保持我们的空气清洁，减少噪音污染，改善水质，提供食品和建筑材料。

youdao

They keep our air clean, reduce noise pollution, improve water quality and provide food and building materials.

他们保持我们的空气清洁，减少噪音污染，改善水质，提供食品和建筑材料。

youdao