Piston cooling fins are located

A．atop the piston crown

B．beneath the piston crown

C．at the base of the piston skirt

D．inside the cylinder liner cooling water jacket

[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]（） is sometimes used for piston cooling since leaks into the crankcase would not cause problems.A . Diesel oilB . Hydraulic oilC . Lube oilD . Mineral oil

[单选题]The cooling of the piston is carried out by circulating （） across the underside of the crown and inside the ring belt or through specially shaped passages.A . sea waterB . scavenging airC . lubricating oilD . fuel oil

[单选题]A separate piston cooling system is used to limit any contamination （） piston cooling glands（） the piston cooling system only.A . between；toB . either；orC . from；toD . neither；nor

[单选题]For diesel engine piston cooling, lubricating oil can be supplied to the pistons by a/an （）.A . oil sprayB . oil bathC . oil control ringsD . drilled passage through the camshaft

[单选题]Fins are installed on the generating tube surfaces in waste heat boilers to （）.A . prevent soot fires in the exhaust systemB . prevent exhaust gas erosion of the tubesC . increase the velocity of exhaust gas flowD . increase the rate of heat transfer

[单选题]fins家族的编码产物是A．生长因子B．生长因子受体C．酪氨酸蛋白激酶D．转录因子

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

[单选题]The street garden is located in _________used to be a market placeA．whichB．whereC．whoD．what

[单选题]The water pockets located on the underside of inflatable liferafts（）.A . stow rainwater; these 4 spaces do not take up valuable spaceB . act as stabilizers by filling with sea water as soon as the raft is inflated and uprightC . hold the freshwater r