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（）

During the diesel engine running, the water level of F.W expansion tank should normally kept in the （） level of glass tube.

The treatment of the fuel oils involves storage, heating, filtering and（）

To shut down a diesel engine after it exceeds the set maximum speed，which type of device listed should be used?（）

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

If two A.C.generators are to be operated in parallel, the load is distributed evenly by（）

The cetane rating of diesel fuel is an indication of the （）

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

For a given exhaust gas boiler, what is the quantity of its evaporation mainly determined?（）