A.tightened up
B.sealed up
C.opened up
D.unscrewed
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A.use
B.release
C.protect
D.effect
A.paved
B.cleaned
C.welded
D.dismantled
A.water
B.oil
C.heat
D.steam
A.safety valve
B.blow down valve
C.scum valve
D.feed check valve
A.strainers
B.valves
C.elements
D.separators
最新試題
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
A grease gun is generally used to lubricate a （）.
When the steering gear is in operation, you should （）.
A pressure drop through the refrigerant liquid line may cause （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
The general purpose of a heat exchanger is to （）.