fresh water是可數(shù)名詞嗎

　　Don't forget that all dogs need a supply of fresh water to drink

　　不要忘記所有的狗都需要喝干凈的水。

　　Fresh water freezes at 0 ℃.

　　淡水在攝氏零度結(jié)冰。

　　Salt water freezes at a lower temperature than fresh water.

　　鹽水冰點(diǎn)溫度比淡水冰點(diǎn)溫度低。