They are less expensive
They are smaller for equivalent pumping ability
They pump more cargo in less time
All of the above
第1题:
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
第2题:
Centrifugal pumps have what advantage(s)over reciprocating pumps ________.
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
第3题:
Robots have one advantage over humans-they never ____ lack of sleep or food.
A.benefit from
B.suffer from
C.stem from
D.result from
第4题:
Absorb erosion of high velocity discharge stream
Seal pump shaft against entry of air
Isolate the discharge side from the suction side
Dampen the turbulent discharge flow
第5题:
Which pump must always be primed ________.
A.Centrifugal pump
B.Reciprocating pump
C.Rotary pump
D.All of the above
第6题:
What is/are the advantage(s)of cranes over conventional cargo booms ________.
A.Cranes are able to pick up and drop loads over a greater spotting area
B.Increased safety because the deck is clear of running and standing rigging
C.Simplicity of operation of the crane by its operator
D.All of the above
第7题:
What is an advantage of a gate valve over a butterfly valve ________.
A.Less frequent maintenance
B.Faster operation
C.Cheaper
D.More compact
第8题:
Paul: Bob, ________________?
Bob: Oh, that's my father! And beside him is my mother.
A、what is the person over there
B、who's talking over there
C、what are they doing
D、which is that
第9题:
第10题:
The high discharge pressure of the rotary pumps permits a larger volume of fluid per unit time than the reciprocating pump
Rotary pumps are capable of pumping more fluid than reciprocating pumps of the same weight
Rotary pumps occupy only one-half the space of reciprocating pumps
Rotary pumps eliminate discharge slippage of the pumped liquid, while this does not hold true for a reciprocating pump