common battery switchboard 共电式交换机

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

manual common battery switchboard 人工共电式交换台

common-battery telephone switchboard 共电电话交换机

common - battery telephone switchboard 共电电话交换机

common battery telephone switchboard [通信] 共电制电话交换机

common n battery switchboard 共电式交换机

multiple common battery switchboard 复接式交换机

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