ThefirstimportantexpositionintheUnitedStateswasheldinPhiladelphiain1876.
A、exhibitionThecontrolsofmostmodernairplanescanbeoperatedeithermanuallyorautomatically.
Alligatorsstillexistinsomeofthedank潮湿swampsandbayous小海湾ofAlabama'scoastalregions.
Bythenineteenthcentury,embroideryonmen'sclothinghadvirtuallydisappearedexceptfortheoccasionaldecorativevestandtie.
InthenortheasternUnitedStates,itrainsintermittently间歇地throughoutthespring.
In1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.
