common battery switchboard 共电式交换机

local battery switchboard 磁石式电话交换机 ; 自带电池电话总机

central battery switchboard 共电式交换台 ; 共电式交换机

manual common battery switchboard 人工共电式交换台

common n battery switchboard 共电式交换机

local l battery switchboard 磁石式电话交换机

cbs central battery switchboard 共电式交换台

multiple common battery switchboard 复接式交换机

manualcleaning separator common battery switchboard 人工共电式交换台

common battery toll switchboard 共电制长途电话交换机