X axis and y axis adopt ball spiral rods with excellent precisions and low friction factors X . y轴采用滚珠螺杆传动精度佳,摩擦系数小。
2.
This small curved to spiral rod - shaped bacterium is found in the surface epithelial mucus of most patients with active gastritis 在大多数急性胃炎病人的黏膜上皮可见小弯曲螺旋状杆菌。