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

Which of the diesel engine components listed increase air density and helps to improve engine operating efficiency?（）

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

The additional mark （）in the Classification Certificate for Machinery means propulsion apparatus is remotely controlled on the navigating bridge control station, and engine assembly control station is unmanned periodically.

The shipboard oil pollution emergency plan will be invalid after （）

（） is not installed on the main switchboar.

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

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

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

Thermostatic steam pressure reducing valves are used in the fuel oil service system to control the（）