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

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

An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.

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

When the steering gear is in operation, you should （）.

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

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

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 （）.

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