单项选择题 If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause maybe （）.

单项选择题 Which of the following conditions can cause above normal air temperature to develop in the intake manifold of a four-stroke/cycle turbo-charged diesel engine?（）

单项选择题 Lubricating oil systems for diesel engine journal bearings are usually lubricated by which of the following types of lubricating oil systems?（）