当轴的转速较高,且只承受较大的径向载荷时,宜选用()
A.深沟球轴承
B.推力球轴承
C.圆柱滚子轴承
D.圆锥滚子轴承
参考答案:A
---How does Jack usually go to work?
---He _____ drive a car, but now he _____ there to lose weight.
A.used to, is used to walk
B.was used to, is used to walking
C.was used to, is used to walk
D.used to, is used to walking
下面造斜定向方法,哪种适合大斜度井眼使用()。
A、间接定向法
B、直接定向法
C、地面连续读数定向法
D、以上都可以