water-quality constituents

例句：

1. 1. The water quality of the river hasbeen deteriorating due to pollution.
   由于污染，这条河流的水质已经恶化。
2. 2.The government is working on improving the waterquality in the city.
   政府正在努力改善城市的水质。
3. 3. The study found that some chemicalsin the water can be harmful to humans.
   研究发现，水中的某些化学物质对人类是有害的。