单项选择题
The （） chamber is enclosed between the cylinder head and piston.
A.lubrication B.injection C.cooling D.combustion
单项选择题 The （） of the lubricant should be sufficient to hold the film together, but it should allow the lubricant to flow easily.
单项选择题 The （） of the diesel oil must not exceed 120 degree Fahrenheit.
单项选择题 The （） is not properly set thus causing either advanced or retarded firing.
