（） pistons have low inertia and high coefficient of thermal expansion.

（） of the A-frames there is a strong cast iron frame called the scavenging air box.

A.At the top
B.At the bottom
C.In the top
D.In the bottom

点击查看答案&解析

（） of an engine crankshaft can be detected by measuring deflections of crank webs for each unit of the engine.

A.Misalignment
B.Length
C.Strength
D.Stresses

点击查看答案&解析