The main purpose of port State control is not to（）

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

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

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

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

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

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.

（）connectors hold best if a wire is accidentally pulled or a connection becomes loose.

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

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