车床的开合螺母机构主要是用来接通活断开从()传来的运动
A. 进给
B. 光杠
C. 车螺纹
D. 丝杠
进行绕组各分接位置电压比的测量时,要求电压比测试仪的精度不低于0.2%电压比电桥精度不低于()。
A. 0.1%
B. 0.2%
C. 0.3%
D. 0.5%
Your facsimile prognostic chart indicates that you will cross the cold front of a low pressure system in about 24 hours.You should().
A. Expect to see cirrus clouds followed by altostratus and nimbostratus clouds
B. Alter course to remain in the navigable semicircle
C. Prepare for gusty winds,thunderstorms,and a sudden wind shift
D. Expect clear weather,with steady winds and pressure,until the front passe
钻井液的含砂量指钻井液中不能通过()目筛(即边长为74微米)的砂子的体积占钻井液体积的百分数。