natural waters

• 天然水体

natural waters的用法和样例：

例句

1. A new micro column preconcentration system with actived alumina being used as sorbent was developed for spectrophotometric determination of trace phosphate in natural water.
   提出了以活性氧化铝微柱预富集分光光度法测定天然水体中的磷酸根。