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

If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.

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

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

Thermostatic expansion valves can be adjusted for （）.

A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.

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

The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.

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

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