【自动化】中继线替续器。trunk: n. 1.树干 (opp. branch); 躯干,身躯 ...relay: n. 1.接替的马;驿马;接替的狗;(备有接替马匹的)旅 ...radio relay trunk service: 无线电接力干线通信业务tr trunk relay: 中继线中继trunk connecting relay: 中继连接继电器下载手机词典可随时随地查词查翻译