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【单选题】
The vibration pump provides the hydraulic drive for vibration motor on the lefthand of the drum, which generates the vibration by _______ the eccentric shaft.
A.
rotating
B.
reciprocating
C.
rotated
D.
reciprocated
举报
参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【单选题】Reduced capacity accompanied by vibration and noise at the suction of a centrifugal pump is a result of ____.
A.
cavitation
B.
Water hammer
C.
Fluid friction
D.
Steam knock
【单选题】Reduced capacity accompanied by vibration and noise at the suction of a centrifuga pump results from the Action of vapor pockets in the water being pumped caused by__
A.
fluid friction
B.
pump knocking
C.
cavitation
D.
water hammer
【单选题】以下不是需求分析阶段的基本任务的是()
A.
调查分析用户活动
B.
收集和分析需求数据，确定系统边界
C.
编写数据库系统总结报告
D.
协助用户明确对新系统的各种需求