- 问题详情: Hundredsofyearsago,lifewasharderthanitistoday.Peopledidn’thavemodernmachines.Therewasnomodernmedicine,either.Lifetodayhasbroughtnewproblems.Oneofthebiggestispollution.Waterpollutionhasmadeourriversandlakesdirty.Itkillsourfishandpollute...
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