解释英语句子（挺多的,耐心点）they see how water is stored and cleaned for

解释英语句子（挺多的,耐心点）
they see how water is stored and cleaned for drinking.
they also learn that everything people do to the land can affect how clean the water is.
students are given chance to practice how to protect the enviroment.
they work as volunteers to examine the water quaily.
they analys what affect the water quality and write their findings in a report.