前置泵进水时，为什么要保持泵出口流量最少80t/h流量？_爱下问搜题

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问题问答题简答题

前置泵进水时，为什么要保持泵出口流量最少80t/h流量？

答案

参考答案：

制造厂规定，前置泵最小流量不低于其额定流量的10％，即58t/h，若流量过小，泵出口压力波动大，泵内声音也大，泵转子容易晃动不稳，产生串轴，使轴承温度升高甚至损坏，泵也容易产生汽蚀，为安全起见，特规定要求前置泵出口流量最低不低于80t/h。

单项选择题共用题干题

下颌缺失，弯制卡环，舌侧为塑料基托连接的义齿蜡型，采用混装法装入型盒，常规去蜡，充填，磨光。

基托表面抛光处理时应保持湿润，其目的是（）。

A.防止基托变形

B.防止卡环变形

C.防止人工牙外形磨损

D.防止基托折断

E.使塑料表面降温

完形填空

One day my math teacher asked me to help him save backup copies of his work in the computer. I then realized I was able to      the grades for all of his classes. I showed him how to copy files from one disk to another and he      me.
A few days later he asked me to help him again, because he      how to do it. When I began to show this to him, some students in my class      and began to talk among themselves     . Later that day, at lunch time, I was      by several of them.
“Hey, could you help us change our grades in math? We’ll      you…”
I could not believe what I was hearing. I could get paid for something very   . “All right, I’ll do it.” The next day my math teacher      me to help him out. When he was not going paying attention, I began to change their grades from F’s to A’s.
I soon became very      among my friends. They began to treat me like a god with magical     . I began to change the grades of students. Word      quickly and I became very rich.
Everything was going fine     I was called into the headmaster’s office. When I got there, my teacher was mad, and the headmaster had an angry      in his eyes. “I have known you for three years now. I don’t want to      what your teacher said, but I’m afraid that I must. He has too much   ,” he said. “do you have anything to say      yourself?” he asked.
“No.” I said finally. I did not realize how serious my actions had been. I had violated the      of my teacher and the headmaster. And there was no way     . I was forced to leave my school. That was a good      for me.

A．disappointedly

D．appreciated

C．interesting