Flame failure in an automatically fired auxiliary boiler can from a/an （）

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

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

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.

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

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

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

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

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

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