A.0.4~2Gy/h B.1~3Gy/h C.2~8Gy/h D.8~12Gy/h E.≥12Gy/h
A.226鐳 B.137銫 C.59鈷 D.192依 E.125碘
60鈷治療機定時器誤差不大于()
A.1% B.2% C.3% D.2.5% E.1.5%