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.

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

（） is not installed on the main switchboar.

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

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