生态系统能量的流动是通过（）进行的。A．消费者B．食物链和食物网C．生产者D．分解者

A cracked diaphragm in a thermostatic expansion valve will cause the valve to _____.

A.return to a neutral position

B.flood the evaporator

C.open

D.close

Thermostatic expansion valve are _____.

A.either all the way open or all the way closed

B.normally open

C.throttled depending on load

D.controlled by suction pressure

When you adjust a thermostatic expansion valve, _____.

A.refrigerant must be bled off the sensing line before adjustments are made

B.all refrigerant must be pumped into the receiver before adjustments are made

C.time must be allowed for conditions to stabilize in the evaporator before further adjustments are made

D.all refrigerant must be routed through the dehydrator while changing the superheat setting

A.open

B.close

C.remain in its position

D.flood the evaporator with refrigerant

A.nonexistent

B.for controlling pressure

C.for controlling superheat

D.for controlling the solenoid valve

A.evaporator pressure decrease

B.evaporator coil over-feed

C.evaporator capacity increase

D.expansion valve diaphragm rupture

If the superheat value of a thermostatic expansion valve is set too low, the _.

A.the suction line will be abnormally cold and liquid may slug back to the compressor

B.the suction line will be hot due to a reduced amount of refrigerant returning to the compressor

C.the temperature of the refrigerant within the condenser will remain the same

D.the temperature of the refrigerant passing through the sub-cooler will decrease

A.either all the way open or all the way closed

B.normally fully open

C.throttled depending on load

D.controlled by liquefied pressure

A.around the engine

B.around the cooler

C.to the expansion tank

D.overboard

When the heat load begins to increase, the needle valve of an expansion valve will______.

A.move in an opening direction

B.move in a closing direction

C.either open or close

D.not move at all