water hardness

例句：

1. 1. The water in the lake is very hard, making it difficult for fish to live there.
   湖里的水非常硬，使得鱼很难在那里生存。
2. 2.To prevent hard water from affecting your skin, you should use a soft sponge.
   为了防止硬水影响你的皮肤，你应该使用软海绵。
3. 3. The mineral content of the water can affect its hardness, which in turn affects the taste and quality of the water.
   水中的矿物质含量可以影响其硬度，进而影响水的味道和品质。