An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.

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

Which of the following statements is correct concerning heat transfer?（）

Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.

Thermostatic expansion valves can be adjusted for （）.

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

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

A salinity indicator is used to determine the （）.

An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.

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