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

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

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

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 suction pressure at the refrigeration compressor is below normal, the cause can be（）.

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

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

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 （）.

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