锅炉给水泵是把除氧器内的水压送至锅炉汽包内,当除氧器液面压强在运行中变化时,随着除氧器内液面压力的不断升高,锅炉给水泵的流量qv和扬程H也将不断变化,其变化规律是( )
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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