filled
evacuated
compressed
charged
第1题：
To add refrigerant to the low side of an air conditioning system, the refrigerant should be introduced through the_______ .
A.suction service valve as a vapor
B.suction service valve as a liquid
C.discharge service valve as a vapor
D.charging valve as a liquid
第2题：
The flash point of a liquid refers to the temperature ______.
A.at which a liquid will give off inflammable（易燃的） vapors
B.at which a liquid will burn steadily
C.at which a liquid will explode
D.that a liquid must reach before it will flow readily
第3题：
Which of the following terms is used to identify the pressure of the liquid entering a pump?
A.Suction head
B.Pump head
C.Discharge head
D.Total head
第4题：
as close to the main engine as possible
as close to the main pump as possible
just before the fuel valve
just before the booster pump
第5题：
Oil is discharged from the impeller through the outlet
Gravity causes the oil to flow toward the discharge
The self-priming feature of the centrifugal pump enables it to draw its own suction as it starts
The discharge capacity varies directly with the speed of the impeller
第6题：
The pressure of a liquid leaving the pump can be referred to as the ______.
A.total head
B.discharge head
C.net positive suction head
D.suction head
第7题：
draw the liquid in；force the liquid out
force the liquid out；draw the liquid in
suction；draw
deliver；outlet
第8题：
Which statement is NOT true?
A.In a simple vane pump, the rotor and cam ring are exactly concentric
B.Balanced vane pump has an elliptical cam ring
C.Liquid in both gear pump and vane pump are forced out to the outlet.
D.Balanced vane pumps can work at a higher pressure than the simple vane pump
第9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10题：
increase discharge pressure
increase suction vacuum
develop pulsation flow
keep a steady rate of flow