whilestudyingthevolc的精選

問題詳情：Inthe1960s，whilestudyingthevolcanichistoryofYellowstoneNationalPark，BobChristiansenbecamepuzzledaboutsomethingthat，oddly，hadnottroubledanyonebefore：hecouldn'tfindthepark'svolcano.Ithadbeenknownfo...