组合机床传动装置中一对交换齿轮的用途是改变切削头转向。()
参考答案:错
颈椎病颌枕带牵引最大重量不应超过
A.6kg
B.5kg
C.10kg
D.1kg
E.15kg
当轴的设计直径为φ30,0.02,0.04时,该轴的实际直径应不大于()mm。
A.30;
B.29.96;
C.29.98;
D.29.94。