To function properly, oil control rings used on a diese

单项选择题

To function properly, oil control rings used on a diesel engine piston must distribute sufficient oil to all parts of the cylinder wall and must also（）.

A.prevent any lubricant from reaching
B.prevent excessive lubrication from reaching the combustion space
C.Provide metal-to-metal contact to seal the cylinder against blow-by
D.assure a positive means of scraping carbon accumulation from the cylinder

船舶电气与船舶安全