电力系统在同一点发生的不对称短路形式有单相接地短路、两相短路和两相短路接地,在发生此类短路时,三相系统处于______运行状态。
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧