Hundredsofyearsago,lifewasharderthanitistoday.People...
问题详情： Hundredsofyearsago,lifewasharderthanitistoday.Peopledidn’thavemodernmachines.Therewasnomodernmedicine,either.Lifetodayhasbroughtnewproblems.Oneofthebiggestispollution.Waterpollutionhasm...