单项选择题
60钴治疗机准直器其轴心线回转时轴心偏差不超过()
A.1mm B.2mm C.3mm D.0.5mm E.1.5mm
A.5mm B.10mm C.15mm D.20mm E.25mm
A.1mm B.2mm C.1.5mm D.2.5mm E.0.5mm