他在用铁锤把那块岩石一小块一小块地敲下来.He was chipping away at the rock with a hammer.工人把铁锤平了.The worker hammered the iron flat.铁锤可以是致命的武器.A hammer can be a lethal weapon....
A frequency of one million megahertz, 10000? 200 Hz.一百万兆赫(兹)频率, 即10000? 200赫(兹)....UHF frequencies of around 900 megahertz.大约900兆赫的超高频率The bandwidth ( megahertz ) and spectrum position of the signal arising from televisi...