已知刮板输送机:q-每米货载质量(kg/m),A-中部槽物料运行的断面积(m2),ρ-物料的散碎密度(kg/m3)υ-刮板链速(m/s),则刮板输送机的运输能力Q为( )t/h
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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