A.They are less expensive
B.They are smaller for equivalent pumping ability
C.They pump more cargo in less time
D.All of the above
您可能感興趣的試卷
你可能感興趣的試題
A.cargo pump pressure gauges
B.crossover lines interconnecting two pumps
C.suction side of pumps
D.atmosphere through pump vents
A.advance
B.cavitation
C.edging
D.slip
A.a not knowing
B.an unknowing
C.an unknown
D.a not known
A.brake
B.devil's claw
C.pawls
D.All of the above
A.sand
B.soft soil
C.stiff clay
D.heterogeneous soil
最新試題
An example of a modern anchor which has a stock is a(n)（）.
In the piping systems of a vessel，what type of valve gives the least resistance to fluid flow when fully open?（）.
The most common type of davit found on merchant vessels today is the（）.
Limit switches are used on which davits?（）
The portable radio apparatus means（）.
As the propeller turns，voids are formed on the trailing and leading edges of the propeller blades causing a loss of propulsive efficiency，pitting of the blades，and vibration. These voids are known as（）.
The extension of the after part of the keel in a single-screw vessel upon which the stern post rests is called the（）.
Cargo pump relief valves are piped to the（）.
If a gasoline engine turns over freely but will not start，the cause is generally（）.
An example of a messenger is a（）.