The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.

The usual symptoms of cavitation in a centrifugal pump is （）.

The general purpose of a heat exchanger is to （）.

The rate of heat transfer from a hot region to a cold region is affected most by the （）.

A grease gun is generally used to lubricate a （）.

On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.

If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.

If the head pressure of a reciprocating refrigeration compressor is excessive, （）.

Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）

The output volume of a positive fixed displacement pump can be changed only by （）.