InthenortheasternUnitedStates,itrainsintermittently间歇地throughoutthespring.
A、steadilyThewheelsofthefirstroadvehicleswerefashionedfromcrudestonedisks.
DoubleEagleinthefirsttransatlanticballoon,wasgreetedbyavidcrowdsinFrance.
TheeconomyofDallas,Texas,isstronganddiversified.
Oneofthegreatestbreakthroughsforprofessionalwomencamein1973whenthefieldofbankingopenedupforthem.
In1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.
