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问题 问答题 简答题

为什么启动离心泵时要关闭出口阀门？

答案

参考答案：

①当泵出口阀门关死时，泵的排量为零，这时泵的功率最小；

②启动时电流为额定工作电流的6~7倍，因此，在启泵时，为减小电动机的启动负荷必须把出口阀门关死。

问答题

Edmund advertised his car in Public Eye, a local newspaper. In response to the advertisement, John called on Edmund on 1 June and offered him R10,000 for the car. Edmund was rather doubtful about John’s ability to pay for the car, but nevertheless agreed to sell the car to John and accepted John’s cheque for R10,000. Edmund allowed John to take the car away and asked his bank to seek immediate payment of John’s cheque. John’ s cheque, however, was dishonoured and on 2 June, Edmund asked the police to recover the car. On 4 June, John sold the car to an unsuspecting Sandy, who bought it in good faith. The police have now been in contact with Sandy concerning the car.Required:In the context of the above information, advise Edmund in relation to,

(b) Sandy’s purchase of the car. (5 marks)
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单项选择题

以下哪项不是告警知识库的基本要素（）

A、告警知识库开发

B、告警知识库体系维护

C、告警知识整理

D、告警知识发布
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