One of the reasons that cause oil flowed from sludge outlet of a self-cleaning separator is（）

Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）

The Port State Control officer may witness a fire drill carried out by the crew assigned to these duties on the（）

To proceed to the assistance of a ship in distress is（）

Diesel engine air start system check valves are opened by （）

Which of the listed governor characteristics will greatly affect the load sharing relationship between paralleled diesel generators?（）

“Insufficiency of manning or insufficiency of certification of seafarers” is an identification of a（）

If separating effect is not good, which measure should be taken （）

The condensers located in various stages of a flash evaporator are cooled by（）

（）are used to digest the sewage to produce innocuous sludge in a biological sewage treatment plant.