Millionsofaircrafttakeoffaroundtheworldeveryyear.Theski...
問題詳情:Millionsofaircrafttakeoffaroundtheworldeveryyear.Theskiestheyflyinseemlimitless-milesofemptyspace.But,withthenumberofflightsincreasingeachyear,thisemptinessnolongerexists.Researchersintheworld...