单项选择题 What color exhaust will be exhibited when a slow speed two-stroke/cycle main propulsion diesel engine, designed to operate on light and heavy fuel oil, is operated on insufficiently preheated heavy fuel oil?（）

单项选择题 Combustion knock will most likely occur as a result of using a fuel with（）

单项选择题 High exhaust temperatures from all of cylinder of a turbocharged, four-stroke/cycle diesel engine can be caused by an（）