In the application of central air-conditioning, the technology of variable-frequency primary pump has been widely studied.

在中央空调的应用过程中，冷冻水一次泵变频技术得到了广泛的研究。

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When applicable, pumps shall be designed to allow for the addition of parallel pump units to be coupled by the primary pump shaft.

如合适，应将泵设计成允许加入与主泵轴相连的平行泵单元。？

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Analyses and confirms the practicability of variable water flow operation for the primary pump system, and illustrates its obvious energy saving effects.

分析了一级泵系统实现变流量运行的可行性，并通过实例说明了其显著的节能效果。

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Taxpayers have less disposable income to pump into the economy while small businesses, the primary drivers of job creation in our national economy, have less money to invest in hiring.

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This is what this data is supposed to monitor, but the well flow evidence would appear to have been ignored, because at this point the BP rig supervisors should have gone to a well kill operation and started to pump heavy mud back into the well bore to restore the primary control mechanism.

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Moreover, many parents of primary or secondary school students find in-person tutoring to be inconvenient, costly (especially at the gas pump), and lacking in quality selection, especially compared to the wider range of tutors found online.

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