单项选择题
A.Increased suction head pressure
B.Decreased feedwater temperature
C.Pump recirculating line being open too much
D.Excessive feedwater temperature
单项选择题 In readying an auxiliary water-tube boiler for a routine hydrostatic test, which of the following procedures should be undertaken prior to filling the boiler with fresh water?（）
单项选择题 The fuel supply system to an automatic auxiliary boiler, will be automatically shutdown if the boiler （）
单项选择题 Lubricating oil is supplied to the crank-pin bearings in a marine diesel engine by （）.