valveman阀门操作者
valven.瓣膜;真空管;阀门;电子管
valve prosthesis人工瓣膜
valve oil shield阀防油罩
valve controller阀控制器
valve oscillator电子管振荡器
valve technology阀门技术
valve-stem nut阀杆螺母
valve stem gland阀杆填料压盖
valve of Sylvius西耳微斯瓣, 下腔静脉瓣
valve stem guide阀杆导承
valve lift curve阀升程图,气门升程曲线,阀升距图