单项选择题
60钴治疗机回转角度指示误差应小于()
A.±0.5° B.±1.5° C.±1° D.±2° E.±2.5°
A.5% B.10% C.15% D.20% E.60%
A.1mm B.2mm C.3mm D.0.5mm E.1.5mm