单项选择题
A.D=DPB.D=D+PC.D钻=D-PD.D=D-P÷D
A.20#B.25#C.30#D.45#
A.盲孔B.通孔C.内孔D.外圆
A.0.1047rad/sB.0.1667rad/sC.6.2831rad/sD.0.1591rad/s
A.光闪式转速表B.电频闪式测速仪C.频闪式转速表D.光频闪式测速仪
A.转速挡B.表盘C.放大倍数D.减小系数
A.周期B.效率C.速度D.距离
A.0.5hB.1hC.1.5hD.2h
A.40kPaB.30kPaC.20kPaD.10kPa
A.12hB.24hC.48hD.72h
A.etB.GC.KD.ρ