单项选择题
A.condensate B.a small amount of make-up feed C.A and B D.None of the above
Proper combustion in a boiler would be indicated by （）....
单项选择题Proper combustion in a boiler would be indicated by （）.
A.yellowish flame B.golden yellow flame C.white flame D.brilliant white flame
Black smoke coming from a boiler can be caused by （）.A....
单项选择题Black smoke coming from a boiler can be caused by （）.
A.low water level B.low oil pressure C.excessively high fuel pressure D.an improper air/fuel ratio
Which of the following pumps belongs to centrifugal pum...
单项选择题Which of the following pumps belongs to centrifugal pump?（）
A.Reciprocating pump B.Screw pump C.Diffuser pump D.Water-ring pump
