介质损耗与（）成正比。
A、外加频率的平方
B、外加电压的平方
C、电源频率
D、外加电压
参考答案：B, C
— How did you find Jennifer Yuh's new film Kung Fu. Panda 2?
— _____.[ ]
A. Oh, wonderful indeed !
B. I went to the cinema alone.
C. First by train and then by ship.
D. A guide showed me the way.
It's said that smoking won't be _______ in indoor public places or workplaces in China soon. [ ]
A. attacked
B. admired
C. attracted
D. allowed
