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刘文勇黄金阅读真题：奥加拉拉蓄水层的枯竭
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DepletionoftheOgallalaAquifer
奥加拉拉蓄水层的枯竭
ThevastgrasslandsoftheHighPlainsinthecentralUnitedStatesweresettledbyfarmersandranchersinthe1880’s.Thisregionhasasemiaridclimate,andfor50yearsafteritssettlement,itsupportedalow-intensityagriculturaleconomyofcattleranchingandwheatfarming.Intheearlytwentiethcentury,however,itwasdiscoveredthatmuchoftheHighPlainswasunderlainbyahugeaquif ...