（） is the breakdown of surface tension between oil droplets in an oil water mixture which causes them to join and increase in size.

Centrifugal pumps are popular because they are very sim...

单项选择题Centrifugal pumps are popular because they are very simple in construction,and produce smooth, constant, （） discharge.

The emergency bilge suction or bilge （） is used to prev...

单项选择题The emergency bilge suction or bilge （） is used to prevent flooding of the ship.

In （） pump a closed discharge valve will not cause exce...

单项选择题In （） pump a closed discharge valve will not cause excessive pressure to build up.