单项选择题
A.slightly acidic condition B.slightly alkaline condition C.overtreatment of water D.neutral condition of water
Which of the following statements concerning fire-tube ...
单项选择题Which of the following statements concerning fire-tube boilers is correct?（）
A.Combustion gases flow through the tubes B.Flames impinge on the tubes C.Combustion occurs in the tubes D.Water flows through the tubes
A diesel engine cooling water system with a pH factor o...
单项选择题A diesel engine cooling water system with a pH factor of 30 indicates a condition of （）.
A.slight acidity B.slight alkalinity C.excessive alkalinity D.excessive acidity
Fuel injectors used in heavy fuel oil systems are usual...
单项选择题Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce（）.
A.cold corrosion of the nozzles B.fuel viscosity for better atomization C.carbon accumulation on the nozzles D.fuel detonation in the cylinders
