The megaphone(microphone) makes the voice sound louder because it points sound waves in one direction and keeps them from spreading out in all directions.
A、slitheringB
暂无解析
TheNativeAmericaninterpreterSacajaweawasavaluablememberoftheLewisanddarkexpeditionin1805.
Thefearofsmallpox,whichterrorizedtheeighteenthcentury,hasnoanalogy(likeness)today.
Communicationisoneofthemostimportantbondsthatholdculturalsystemstogether.
Somecosmeticsmanufacturersattempttocapturetherose'sunmistakablefragrance香味insoapsandperfumes.
TheSalkvaccineisamajorfactorinthefighttoeradicatepolio.
