The lower section of a piston is called the （）.

[单选题]An aluminum piston has lower inertia and higher coefficient of （） compared to that of cast iron.A . viscosityB . twisting momentsC . inertiaD . thermal expansio

[单选题]The lower end of each piston rod is reduced in diameter to fit a bore in the （）, this being secured to the piston rod by a nut.A . piston gudgeon pinB . piston skirtC . cross-headD . cross-head pi

[单选题](piston area)×(piston stroke)×(numbers of the cylinders)=engine( ).A．brake horsepowerB．displacementC．cylinder volumeD．cylinder clearance

[单选题]lower the gangwayA．调整舷梯B．放舷梯C．收舷梯D．摆动舷梯

[单选题]lower a littleA．升一点儿B．把定C．调整D．降一点儿

[单选题]As to the piston cooling, of the following, which statement is not true?（）A . Because the piston is exposed to very high temperature, it must be cooledB . The lower the piston cooling temperature is, the better it isC . Both water and lube oil can be

[单选题]The piston rings are manufactured with a diameter （） the bore of the cylinder.A . larger thanB . smaller thanC . equal toD . none of the above

[单选题]The lowest ring of a piston is （）.A . a coil springB . a sealing ringC . an oil distributor ringD . main seal ring

[单选题]英语PISTON指（）A .活塞B .开关C .按钮D .弹簧

[单选题]In an engine with a pot-shaped piston, some lubricating oil from the main bearing will pass along a drilled passage in the crankshaft to the bottom end bearing and then up a connection rod to theA．crossheadB．crankpinC．crank journalD．gudgeon pin