A.愈小B.愈密C.愈大D.愈慢
A.超聲場(chǎng)B.超聲波C.近場(chǎng)區(qū)D.遠(yuǎn)場(chǎng)區(qū)
A.1.365mmB.0.572mmC.2.48mmD.1.38mm