60鈷治療機(jī)經(jīng)修整的半影區(qū)寬度不超過(guò)()
A.5mm B.10mm C.15mm D.20mm E.25mm
60鈷治療機(jī)等中心誤差應(yīng)不大于()
A.1mm B.2mm C.1.5mm D.2.5mm E.0.5mm
60鈷機(jī)的工作環(huán)境的要求是()
A.環(huán)境溫度15~35℃,相對(duì)濕度30%~75% B.環(huán)境溫度10~20℃,相對(duì)濕度30%~60% C.環(huán)境溫度10~15℃相對(duì)濕度30%~80% D.環(huán)境溫度10~25℃,相對(duì)濕度30%~70% E.環(huán)境溫度15~25℃,相對(duì)濕度20%~60%