单项选择题
Which of the following conditions may need to be reduced when operating a large, low speed, main propulsion, diesel engine at low loads?（）
A.Injection pressures B.Control air supply pressure C.Cooling water flow through after-coolers D.Lube oil temperature
单项选择题 The procedures recommended for auxiliary boilers having high salinity include （）.
单项选择题 Excessive alkalinity of the water in an auxiliary boiler can cause （）.
单项选择题 The purpose of the delivery check valve used in a diesel fuel injection jerk pump is to （）.
