ThefirstimportantexpositionintheUnitedStateswasheldinPhiladelphiain1876.
A、exhibitionIn1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.
Peoplewhodonotsleepenoughtendtobecomeirritable.
Some children display an unquenchable 难以抑制的 curiosity about every new thing they encounter.
Thecontrolsofmostmodernairplanescanbeoperatedeithermanuallyorautomatically.
Thefirstpaperwasmadefromthebarkofthemulberrytree.
