Before liquid can flow into a pump, the air in the suction line must be （） sufficiently to cause the liquid to flow into the suction chamber.

Generally speaking, suction heads require to be （） for ...

单项选择题Generally speaking, suction heads require to be （） for high speed or large capacities than for low speed or small capacities.

Some of the energy fed into the pump will be dissipated...

单项选择题Some of the energy fed into the pump will be dissipated as （） due to mechanical inefficiencies, the remainder will be converted into pressure rise and fluid velocity.

Every liquid has a pressure at which it will vaporize a...

单项选择题Every liquid has a pressure at which it will vaporize and this pressure varies with temperatureThe word “which” means （）.