单项选择题
Poor quality fuel being used in a turbocharged medium-speed, diesel engine could result in （）
A.hard starting B.excessive fuel consumption C.loss of power D.all of the above
单项选择题 Many diesel engine exhaust valves are being constructed with hollow stems filled with sodium in order to （）
单项选择题 Cracking of a diesel piston crown can result from（）
单项选择题 In an auxiliary diesel engine, the reason for knurling the piston skirt is to（）
