Themegaphone(microphone)makesthevoicesoundlouderbecauseitpointssoundwavesinonedirectionandkeepsthemfromspreadingoutinalldirections.
A、slitheringSomeanimalspantandsweattospeedevaporationofbodymoistureandthuscoolthemselves.
TheNativeAmericaninterpreterSacajaweawasavaluablememberoftheLewisanddarkexpeditionin1805.
Themegaphone(microphone)makesthevoicesoundlouderbecauseitpointssoundwavesinonedirectionandkeepsthemfromspreadingoutinalldirections.
Bythenineteenthcentury,embroideryonmen'sclothinghadvirtuallydisappearedexceptfortheoccasionaldecorativevestandtie.
Insectpestsareamongtheleadingcausesofcropfailure.