Themegaphone(microphone)makesthevoicesoundlouderbecauseitpointssoundwavesinonedirectionandkeepsthemfromspreadingoutinalldirections.
A、slitheringCometsarestillregardedwithawebysomepeople.
Thewheelsofthefirstroadvehicleswerefashionedfromcrudestonedisks.
Urbanrenewalprogramsstrivetoupgradeareasthatarebecomingslums.
Oneofthegreatestbreakthroughsforprofessionalwomencamein1973whenthefieldofbankingopenedupforthem.
In1861itseemedinevitablethattheSouthernstateswouldbreakawayfromtheUnion.
