单项选择题
In the combustion chamber, the part whose surface is exposed to the highest temperature is the （）.
A.cylinder liner B.cylinder cover C.piston D.exhaust valve
单项选择题 As to the bearing, of the following, which statement is not true?（）
单项选择题 As to the piston cooling, of the following, which statement is not true?（）
单项选择题 The essential part of the diesel engine, whose function is to convert the heat energy into the mechanical power, is the （）.
