60鈷治療機(jī)定時(shí)器誤差不大于()
A.1% B.2% C.3% D.2.5% E.1.5%
60鈷治療機(jī)照射野內(nèi)有用射線空氣比釋動(dòng)熊率不對(duì)稱性應(yīng)小于()
A.5% B.10% C.15% D.20% E.60%
A.0.5 B.1 C.1.5 D.2 E.2.5