空气包利用气体的压缩和膨胀性来贮存或释放液体,使多缸往复泵吸入总管或排出总管内的液流趋于均匀,惯性力减小,降低压力波动,同时还可以防止泵在较高冲次下产生水击现象等。( )
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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