输电回路各端均断开时，该输电回路记为停运。
参考答案：错
— Thank you very much.
— _____. [ ]
A. That's all right
B. That's right.
一口袋装有3只红球，2只黑球，今从中任意取出2只球，那么这2只球恰有一红一黑的概率是3/5
