单项选择题
A.the indicators B.the starting valves C.the cylinder lubricators D.the turning gear
Before starting the engine the air bottle should be （）....
单项选择题Before starting the engine the air bottle should be （）.
A.pumped up B.loaded C.discharged D.opened
Before replacing a piston you should check the rings to...
单项选择题Before replacing a piston you should check the rings to see that all clearances and gaps are within the permissible （）.
A.deflection B.discrepancy C.error D.tolerance
单项选择题Before replacing a piston you should check the rings to see that all clearances and gaps are （） the permissible tolerances.
A.above B.at C.over D.within
