單項(xiàng)選擇題What is the function of wearing rings found on some centrifugal pumps? （）

A.Absorb erosion of high velocity discharge stream
B.Seal pump shaft against entry of air
C.Isolate the outlet side from the inlet side
D.Dampen the turbulent discharge flow


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1.單項(xiàng)選擇題What is the best indication of the loading of a diesel engine?（）

A.Oil temperature
B.Manifold pressure
C.Exhaust gas temperature
D.Fuel consumption

2.單項(xiàng)選擇題What is NOT a responsibility of the tankerman in charge of loading an unmanned tank barge? （）

A.Enforcement of smoking restrictions
B.Restricting vessels from coming alongside the barge
C.Insuring that a combustible gas indicator is aboard
D.Protecting cargo hose with chafing gear

3.單項(xiàng)選擇題What is NOT a precaution to be taken when topping off? （）

A.Reduce the loading rate
B.Notify the engine room of the procedure
C.Maintain communications with the dock man
D.Give the operation your undivided attention

4.單項(xiàng)選擇題What is an example of the term Restraint of Rulers，Princes，or Peoples in a marine insurance policy? （）

A.A prohibition from loading a cargo from a country when the cargo may be a carrier of infectious diseases
B.Arrest of a vessel by legal authorities to satisfy claims through exercise of a maritime lien
C.Damage caused by riot of the population of a port
D.Losses caused by fines from polluting the harbor after malfunction of a piping system

5.單項(xiàng)選擇題What is a characteristic of all centrifugal cargo pumps? （）

A.They are self-priming
B.Decreasing the speed of rotation will decrease the discharge pressure
C.Opening the discharge valve wider will increase the discharge pressure
D.All of the above