"淡水"怎么用英语翻译

淡水:
1. (n) potable water; water with low salt content
2. fresh water (FW)
3. freshwater
4. sweet water
5. plain water

Examples:
1. 盐水比淡水浮力大。
Salt water is more buoyant than fresh water.
2. 这个淡水湖里有许多种鱼。
There are many fish in this freshwater lake.
3. 过去这些年来，用蒸馏法制取淡水成本一直很高。
In the past, obtaining fresh water by distillation has always been too expensive.
4. 湖泊学研究淡水，尤指湖泊和海洋的生命和现象的科学研究
The scientific study of the life and phenomena of fresh water, especially lakes and ponds.

淡水生态
freshwater ecology
淡水够用吗？
Will our water last?
淡水雨淋险
Risk of fresh and / of rain water damage(wetting)
淡水；无咸味黄油
sweet water; sweet butter.
一个流入淡水的湖
a lake fed by a freshwater inflow.
一个流入淡水的湖
A lake fed by a freshwater inflow.
咸水比淡水浮力大。
Salt water has more buoyance than fresh water.
他们所必需的是淡水。
Their need was fresh water.
湖内陆的大型淡水或咸水水