活度计工作原理为电流电离室，其工作区为（）。
A.饱和区
B.不饱和区
C.正比区
D.反比区
E.G-M区
参考答案：A
My father knows much about Beijing Opera, but my mother _______.[ ]
A. can't
B. isn't
C. doesn't
D. didn't
红外测温仪也可以透过玻璃进行测温。
