1、用图解直接法求离心泵工况点的步骤（并画出示意图），说明为什么离心泵特性曲线与离心泵装置的管道特性曲线的交叉点K即为离心泵装置的工况点？手写，绘示意图，拍照上传
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Where does this conversation most likely take place?
A. In a motel.
B. In a restaurant.
C. In the post office.
D. In the railway station.
How long will the woman wait according to the man?
A. 15 minutes.
B. 5 minutes.
C. 10 minutes.
D. 50 minutes.
Why does the man apologize the first time?
A. Because he doesn’t recognize the woman.
Because the woman has a reservation.
C. Because there are no vacancies left.
D. Because he hurts the woman’s feeling.
Why does the man apologize the second time?
A. Because he smokes in front of the woman.
Because he shouts at the woman.
C. Because he made a little mistake.
D. Because he doesn’t understand the woman.
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