同步电动机的特点之一是稳定运行时的转速n与定子电流的频率f1之间有严格不变的关系,即同步电动机的转速n与旋转磁场的转速n0相同。( )
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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