anechoic area无: not have; there is not; be w ...回声: echo; bounce back; reverbera ...区: H region; H平: flat; level; even; smooth段: section; segment; part; para ...下载手机词典可随时随地查词查翻译关注微信公众号:chachacidian,回复:无回声区,平段,即可在微信中查询翻译