Thecontrolsofmostmodernairplanescanbeoperatedeithermanuallyorautomatically.
A、bythebookHowmanypeopleareawarethatadancerwiththeNewYorkCityBallettypicallywearsoutaminimumoftwohundredpairsoftoeshoesperyear?
The Salk vaccine is a major factor in the fight to eradicate polio.
Comets are still regarded with awe by some people.
Alligators still exist in some of the dank 潮湿 swamps and bayous小海湾 of Alabama's coastal regions.
Themegaphone(microphone)makesthevoicesoundlouderbecauseitpointssoundwavesinonedirectionandkeepsthemfromspreadingoutinalldirections.
