A purge recovery system is used in a centrifugal air conditioning or refrigeration system to （）

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

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

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

When does auxiliary burner of incinerator put into operation? （）Ⅰ. start incinerator when it is coldⅡ. the sludge for dealing with is littleⅢ. the sludge for dealing with is largeⅣ. the water and impurity in sludge are too muchⅤ. the temperature in incinerator is lowⅥ. dealing with little solid rubbish

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

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

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

Under MARPOL Code the ship to which it applies has to carry （）

Using a file without a handle may result in （）