fouled tubes in shell and tube condenser
too little or too warm condenser water
air or non-condensable gas in system
overcharge of refrigerant
第1题：
Low compressor head pressure in a refrigeration system can be caused by ___.
A.insufficient condenser cooling water
B.excessive condenser cooling water
C.air in the refrigeration system
D.excessive refrigerant in the system
第2题：
Persons who have swallowed a non-petroleum based poison are given large quantities of warm soapy water or warm salt water to ______.
A.induce vomiting
B.absorb the poison from the blood
C.neutralize the poison in the blood
D.increase the digestive process and eliminate the poison
第3题：
When you go shopping and want to buy some clothes，you should think about which kind of clothes you really need and decide how_____money you can _____on them. Then look at the labels that are inside the new clothes. They tell you how to _____the clothes. The label for a shirt may tell you to wash it in warm water. A sweater label may tell you to wash it in cold water. The label on a coat may say “dry clean only” and cleaning in water may _____this coat. If you do _____the directions say on the label, you can keep your clothes looking their best.
1.A. much
B. many
C. large
2.A. cost
B. spend
C. take
3.A. take place of
B. take use of
C. take care of
4.A. change
B. replace
C. ruin
5.A. as
B. by
C. for
第4题：
low water level
high water level
excessively high fuel pressure
low oil temperature
第5题：
A frontal thunderstorm is caused by ______.
A.pronounced local heating
B.wind being pushed up a mountain
C.a warm air mass rising over a cold air mass
D.an increased lapse rate caused by advection of warm surface air
第6题：
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?
A.A shortage of liquid refrigerant.
B.Excessive frost on the evaporator.
C.Excessive condenser cooling water.
D.Insufficient condenser cooling water flow.
第7题：
What represents poor sanitary procedures ________．
A.Keep and use a separate filling hose for potable（drinking）water
B.Locate potable（drinking）water tanks as low as possible in the bilge
C.Eliminate enclosed spaces in which trash，food particles，dirt may gather
D.After washing dishes with soap and warm water，sterilize them in water of at least 170℉（76.7℃）
第8题：
If a refrigeration compressor is short cycling on high head pressure, you should
A.purge the condenser if the waterside is dirty
B.check for proper water flow through the condenser
C.increase the high pressure cutout setting
D.reduce the cooling water flow
第9题：
insufficient condenser cooling water
excessive condenser cooling water
air in the refrigeration system
excessive refrigerant in the system
第10题：
closed discharge valve
broken pipe line
worn shaft
both A and B