lss looswitching system环路: loop; ring circuit contour; ...交换: exchange; swap; interchange; ...系统: system线路交换系统: circuit switching system数据电路交换系统: data circuit switching system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:环路交换系统,即可在微信中查询翻译