Assoonasearlypeoplesestablishedsettlementtheyhadtheproblemofgettingridofsewage——theirorganicwastesand,sometimes,thoseofdomesticanimals.Naturedisposesofsurplusorganicmaterialinfourprincipalwaysbydilution,oxidation,putrefaction,andfiltration.Earlypeoplesrel (共 5829 字) [阅读本文] >>