单项选择题
Which of the following devices is a common basic element with nearly all mechanical governors?（）
A.Power piston B.Control rack C.Weights acted on by centrifugal force D.Isochronous droop spring
单项选择题 A change in the degree of fuel atomization in a diesel engine would most greatly affect （）.
单项选择题 Scale and dirt accumulation in the waterside of a lube oil cooler will be indicated by a gradual increase in the lube oil（）.
单项选择题 The lower section of a piston is called the （）.
