通常雷暴云上部荷（），下部荷负电荷，云底荷少量正电荷。
参考答案：正电荷
I ______ it everywhere, but I didn’t _____ it.
A．looked for, looked for
B．looked for, find
C．found, looked for
D．find, look for
现代足球运动有何特点？有何作用？
