Themegaphone(microphone)makesthevoicesoundlouderbecauseitpointssoundwavesinonedirectionandkeepsthemfromspreadingoutinalldirections.

Creamoftartar酒石,aweakacid,canbeaddedtoeggwhitestohelpthemfoam泡沫whentheyarebeaten

Alllivingorganisms,regardlessoftheiruniqueidentity,havecertainbiological,chemical,andphysicalcharacteristicsincommon.

Someseaurchins海胆havevenomous(toxin)spines

Incalculatingthedailycalorierequirementsforanindividual,variationsinbodysize,physicalactivity,andageshouldbetakenintoaccount.