人体处于交变电场中，人体体表就有电场，人体对体表交变电场的感知水平为（）（要求写出单位）
参考答案：240kV/m
— How much do you know about the 3D film technology?
— A little. Not until ________ the hot movie Avatar ________ some about it.
A．did I see; did I begin to learn
B．I saw; I began to learn
C．I saw; did I begin to learn
D．did I see; I began to learn
除哪项外，均是秦艽的功效（）
A.祛风湿
B.止痹痛
C.利水消肿
D.退虚热
E.清湿热
