The oil in a cargo winch gear box should be sampled periodically to ().
A. prevent the gear box from leaking
B. prevent the oil from becoming inflammable
C. make sure it has not become contaminated
D. make sure the motor bearings are lubricated
施工监理的内容包括:预算监督、施工项目监督、()。
A. 岗位监督
B. 施工队伍监督
C. 施工进度监督
D. 施工规划监督
铣削平面时,铣刀刃在切入时应由上至下。刮削较大内孔端面时,应()。背刮端面时,应手动断续进给。
A. 采用内孔支承
B. 采用导套支承
C. 不用支承