我们必须保护这条河使其免受污染的翻译：We must protect the River from pollution 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

We must protect the river against pollution

We must protect the River from pollution

We must protect this river to cause it to exempt are polluted

We must protect this river to protect it from pollution

We must protect the River from pollution