单项选择题
Following an overhaul of a crosshead type diesel engine, the engine is jacked over with the turning gear as part of the pre-start procedure, which of the listed pre-start procedures should be carried out?（）
A.Ensure proper cylinder lube oil flow B.Open all air space drain cocks C.Open all indicator valves D.all of the above
单项选择题 Fuel oil is regularly transferred to the day tank in order to （）
单项选择题 Starting air valves are held firmly on their seats by（）
单项选择题 The depth of fuel oil in a tank is normally measured through the（）
