| 1. | Since agriculture accounts for nearly 70 percent of the world ' s fresh water withdrawn from rivers , lakes , and underground aquifers for human use , the greatest potential for conservation lies with increasing irrigation efficiency 自从农业的估计世界上的新鲜水有近70 %将从河川,湖泊及地下水供人使用起,水保育的强大潜力是增加有效灌溉。 |