翻译：如果没有那个工厂的话，水污染会少多少啊！

如果没有那个工厂的话，水污染会少多少啊！
If there was no that factory, how much the water pulltion would have been reduced?

The water pollution will be much less without that factory.

If there were not that factory, the water pollution would be much lighter.

the water pollution would reduce much without that factory

译文：If there was not the factory, the water pollution would be much lighter.

如果不换语气，这个句子变成一般疑问句，那就是：If there was not the factory,How much less water pollution?