The flash point of a residual fuel oil should be used to determine the highest temperature to which oil may be heated（）

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

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

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

The ISPS Code consists of a mandatory section-Part A, which shows（）

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

Using a file without a handle may result in （）

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

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

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.