海底无缝管线管
submarine seamless line pipe
X80电阻焊管线管
X80 grade electric resistance welding linepipe
地下管线管理
underground pipeline management
Management of Underground Pipelines
地下管线管理系统
underground pipeline management system
服务存取控制器管理
service access controller administration
复输出管制器
multiple output controller
钩形集极晶体管管线
hook collector transistor