直流怎样验电?
参考答案:
一手用验电笔验电,另一只手接地。
Nobody enjoys _____. [ ]
A. being looked down upon
B. looking down upon
C. being looked down
D. to look down
岩浆岩转化为岩浆的过程必须经过()
A.搬运作用
B.变质作用
C.喷出作用
D.熔化作用