What color exhaust will be exhibited when a slow speed two-stroke/cycle main propulsion diesel engine, designed to operate on light and heavy fuel oil, is operated on insufficiently preheated heavy fuel oil?（）

A、White

B、Black

C、Blue

D、Clear

If a diesel engine starts firing, but is unable to come up normal speed, either without load or even under a small load, the cause may be （）

A、insufficient fuel supply

B、faulty governor

C、high exhaust back pressure

D、all of the above may cause this problem

About the jacket water, that of the auxiliary engines usually（） is circulated by pumps, and the main engine usually （）

A、an engine-driven；as well

B、an engine-driven；has an independent pump

C、an independent；as well

D、an independent；has an engine-driven pump

One characteristic of a lubricating oil adversely affecting the result of centrifuging is （）

A、high TBN value

B、low oil floc point

C、low oil demulsibility

D、low oil neutralization number

At the beginning of the watch the current operational parameters and the condition of all machinery should be verified and also the log readings should correspond with those （）.

A、noted by the bridge officer

B、told by last duty engineer

C、observed

D、in the instruction manual

Sacrificial zinc anodes are used on the saltwater side of diesel engine heat exchangers to（）.

A、reduce electrolytic action on heat exchanger metals

B、keep heat transfer surfaces shiny and clean

C、prevent rapid accumulation of marine growth

D、provide a protective coating on heat exchanger surfaces