单项选择题
A.air in the cooling system
B.an overhauled water pump
C.correct amount of coolant
D.no air in the cooling system
单项选择题 The rotary motion of a diesel engine crankshaft is obtained from the up and down motion of the piston via the （）.
单项选择题 High diesel engine cooling water temperatures can be caused by （）.
单项选择题 The linear motion of a diesel engine piston is converted to the rotary motion required to drive gears, propeller shafts, and generators by the （）.