单项选择题
A.pilot valve opening
B.compensating needle valve
C.compensating spring tension
D.accumulator spring tension
单项选择题 Which of the following methods is normally used to lubricate bearings in a small high-speed diesel engine?（）
单项选择题 Friction developing between the moving parts of a governor, governor linkage and control valve will cause the governor to （）.
单项选择题 Fusible plugs are installed in fire-tube boilers to （）.