短語詞組短語telegraph grade channel [通信]電報級信道;電報級信道英語CT Carrier Telegraph channel 載波電報信道telegraph voice frequency channel [通信]電報音頻通路interband telegraph channel 帶間電報通路public telegraph channel 公衆(zhòng)電報電路telegraph -grade channel 電報級信道英語telegraph channel transmission equipment 報路傳輸設備single channel radio telegraph system 單路無線電報系統(tǒng) 返回 telegraph channel