But one thing is very important: you don't only have surface water, you also have groundwater and it's much more difficult to see when that is being polluted or when it's being overexploited.
一个国家不仅有地表水,还有地下水,但很难看出地下水被污染或被开采过度。
英汉网英语在线翻译词典收录了3779314条英语词汇在线翻译词条,基本涵盖了全部常用英语词汇的中英文双语翻译及用法,是英语学习的有利工具。