three pads三支撑掌threenum.三n.三；三个adj.三个的three phase bridge rectifier三相桥式整流器three-step nursing process三步法护理程序three circles freezing pipes三圈管three links and one guidance三环一导Three Gorges Reservoir areas三峡库区three-cylinder single lens等径三圆简单透镜three-dimensional modeling三维建模three-dimensional location三维定位算法three - phase power supply三相电源Three dimensional management三维管理