Which of the listed pumps is NOT a positive displacement pump?（）

If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.

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

The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.

Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）

The major source of chemical contaminants in hydraulic fluid is （）.

A pressure drop through the refrigerant liquid line may cause （）.

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

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

Thermostatic expansion valves can be adjusted for （）.