放射防护的基本原则是（）
A.实践的正当化
B.放射防护最优化
C.个人剂量限值
D.机房的防护
E.患者的防护
参考答案：A, B, C
—Did you have a soccer _______ with the team in No.14 Middle School.
—No, There is going to _______ a game next week.
—Oh, that's good. Match yourself _______ them _______this game.[ ]
A. match, be, of , in
B. match, is, with, on
C. match, be, with, in
D. match, are, against, on
CISCO路由器特权模式下的提示符是（）.
A、hostname>
B、hostname#
C、hostname$
D、hostname：
