按照射野输出因子(OUT)的定义,它相当于是()。
A.准直器散射因子Sc
B.模体散射校正因子Sp
C.总散射校正因子Sc,p
D.辐射权重因子ωR
E.楔形因子Fw
参考答案:A
I ____ to reach the manager for the last two hours but the line is always busy. [ ]
A. tired
B. have tired
C. had tired
D. have been trying
张婓、杜预认为法律的基本精神是()
A.律
B.刑
C.礼
D.乐