球轴承套管式转向柱
tube and ball type steering column
球轴承套管式转向管柱
tube and ball type steering column
球形压水室扩散管
orbicular pumping chamber diffusion tube
球形内管冷凝器
condenser with bulbed inner tube
球形3He正比计数管
spherical3He proportional counter
球囊导管扩张术
balloon dilation
Balloon ductal dilatation technique