【简答题】10) 一台 250 r/min , 50Hz 的同步电机,其极数是多少?
【单选题】All the guests at the party were dancing and singing happily _____ the electricity was cut off.
【单选题】The party lasted _____ midnight.
【单选题】—Did you have a good time at the party? —_______ We all enjoyed it so much that it lasted until midnight.
【简答题】请简述居住区道路布局形式有哪些,其各自的特点是什么,并用图纸进行说明。
【判断题】能源消费弹性系数越大,说明国民经济产值每增加1%,能源消费的增长率越高。
【简答题】什么叫同步电机?一台250r/min,50Hz的同步电机,其极数是多少?