单项选择题
A.fire-tube controlled circulation B.fire-tube supercritical circulation C.water-tube natural circulation D.water-tube express circulation
Which of the lists forms of heat transfer, if any, is i...
单项选择题Which of the lists forms of heat transfer, if any, is illustrated by the flow of combustion gases through a boiler?（）
A.Natural convection only B.Forced convection only C.Both natural convection and forced convection D.None
Auxiliary boilers can be classified as（）A.water-tube na...
单项选择题Auxiliary boilers can be classified as（）
A.water-tube natural circulation boilers B.fire-tube boilers C.water-tube forced circulation boilers D.all of the above
When the tilting box of a variable stroke axial-piston ...
单项选择题When the tilting box of a variable stroke axial-piston pump is perpendicular to the pump shaft, which of the following conditions will exist?（）
A.The pistons reciprocate B.The ‘B’ end cylinder barrel rotates C.There is no fluid flow D.Power is transmitted hydraulically
