Themegaphone(microphone)makesthevoicesoundlouderbecauseitpointssoundwavesinonedirectionandkeepsthemfromspreadingoutinalldirections.
A、slitheringAlllivingorganisms,regardlessoftheiruniqueidentity,havecertainbiological,chemical,andphysicalcharacteristicsincommon.
Eyespots, the most rudimentary eyes, are found in protozoan原生动物 flagellates 鞭毛虫 , flatworms 扁形虫 , and segmented worms片段 蠕虫 .
The future survival of the bald eagle is still an important American ecological concern.
Bats fly, rather than glide, and thus are the only mammals capable of true flight.
ThecompanyissuesanannualreporteveryMarch.
