industrial trunk route [工经] 工业干线

north-south trunk route 南北大动脉

domestic trunk route network 国内干线网络

trunk route diagram 中继路由图

international trunk route 国际航路干线

trunk air route [军] 军用航空干线

Only-route Trunk Group 唯一路径干线群

trunk line route 干线径路

trunk mail route 干线邮路