单项选择题
In （） pumps a closed discharge valve will cause bursting discharge pressure.
A.centrifugal B.plunger C.injector D.water
单项选择题 The volute pump is one in which the impeller （）.
单项选择题 Which of the following pumps belongs to centrifugal pump?（）
单项选择题 The pump discharge pressure will be considerably higher than the pressure at the （）.
