Which of the following may cause that the compressor cuts off on high pressure cutout in a refrigeration plant? （）
(1) faulty condensing
(2) too few refrigerant
(3) high discharge pressure
A.any of (1) and (3)
B.any of (1) and (2)
C.any of (2) and (3)
D.any of (1), (2) and (3)
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A.cutout
B.controller switch
C.pressure controller
D.cutout switch
A.evaporator
B.compressor
C.condenser
D.none of the above
A.nonexistent
B.for controlling pressure
C.for controlling superheat
D.for controlling the solenoid valve
A.compressor
B.condenser
C.throttle valve
D.evaporator
A.open-type
B.hermetic
C.semi-hermetic
D.all the above
Which of the following will be desirable properties of refrigerant?（）
(1) non-explosive
(2) non-corrosive
(3) that it doesn’t react with lubricants
A.(1), (2) and (3)
B.(1) and (2)
C.(1) and (3)
D.(2) and (3)
A.saturated
B.super-cooled
C.wet
D.superheated
A.extracts
B.releases
C.gives no
D.absorbs no
A.vapor
B.liquid
C.solid
D.None of the above is tree
A.above
B.below
C.equal to
D.None of the above
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