A.globe valves
B.butterfly valves
C.gate valves
D.reducing valves
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A.a sewage treatment plant
B.the extended aeration process
C.the liquor
D.the bubbling air
A.in boiler drums
B.in refrigerating plants
C.in starting air pipes
D.in air coolers
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By comparing the exhaust gas temperature of each cylinder, the operator can determine if the load is balanced throughout the engine. The device most commonly used is a（）
A purge recovery system is used in a centrifugal air conditioning or refrigeration system to （）
The shipboard oil pollution emergency plan will be invalid after （）
Which of the following items don’t belong to dock repair works?（）
Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）