Aluminum pistons have （） coefficient of thermal expansion compared with those of cast iron.

[单选题]An advantage of aluminum pistons, when compared to cast iron pistons is （）.A . greater high temperature strengthB . better heat conductivityC . greater weight per cubic inchD . increased resistance to wear

[单选题]（） pistons have low inertia and high coefficient of thermal expansion.A . Cast ironB . Cast steelC . Forged steelD . Aluminum

[单选题]Aluminum lifeboats are subject to damage by electrolytic corrosion (the aluminum being eaten away). In working around boats of aluminum you must be very careful（）.A . to keep the boats covered at all timesB . not to leave steel or iron tools lying in

[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

[名词解释] 通透系数（permeability coefficient）

[单选题]（） provide the water to the pistons.A . Pneumatic pipesB . Hydraulic pipesC . Telescopic pipesD . Operating gas pipe

[名词解释] 反应性系数 reactivity coefficient

[名词解释] 分配系数（partition coefficient）

[名词解释] 腐殖化系数 humification coefficient

[单选题]Pistons may be made in （） in order to keep the weight down for balancing purposes at high speed.A . cast ironB . forged steelC . stainless steelD . aluminum alloy