Before starting the engine the air bottle should be （）.

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

点击查看答案&解析

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

点击查看答案&解析