[通信] 环路断续拨号制 loop disconnect pulsing: 回路断路脉冲发送制loop-disconnect pulsing: 环路断开脉冲发生loop pulsing: 回路脉冲法pulsing system: 脉冲系统; 脉冲制; 脉动装置loop-battery pulsing: 环路电池脉冲发生下载手机词典可随时随地查词查翻译