【简答题】
A、长约50mm,锥度为1:20,大端比管孔大0.025~0.05mm B、长约40mm,锥度为1:25,大端比管孔大0.025~0.05mm C、长约40mm,锥度为1:20,大端比管孔大0.025~0.05mm D、长约50mm,锥度为1:25,大端比管孔大0.025~0.05mm
A、长约50mm,锥度为1:20,大端比管孔大0.025~0.05mm B、长约40mm,锥度为1:25,大端比管孔大0.025~0.05mm C、长约40mm,锥度为1:20,大端比管孔大0.025~0.05mm D、长约50mm,锥度为1:25,大端比管孔大0.025~0.05mm