当电缆绝缘内有一个缺陷，加上电压后，还没有发生击穿前，这个缺陷肯定在放电，此时的放电电流是脉冲电流。
参考答案：对
-Four o'clock in the morning?
-What? Oh, no, don't ring me up that early. I ________.[ ]
A．will sleep
B．will be sleeping
C．am sleeping
D．am going to sleep
