A . an oil seal
B . removing heat
C . a gas seal
D . cooling the pisto
[单选题]All the rings are slightly rounded on their external top and bottom edges to keep the oil film on the cylinder liner during () for new piston rings.A . the running-in periodB . the running processC . gas exchange processD . the boiler firing
[单选题]The selection of an oil depends () on the operating conditions, the design of the engine and the type of fuel to be burned.A . to a great extentB . on a great extentC . on mainlyD . on only
[试题]A.gain, differences between people and the opportunity for natural selection to take advantage of it have diminished.
[单选题]The cleaned heated oil, after passing through the centrifuges, is to be pumped to a ().A . settling tankB . service tankC . ballast tankD . drain tank
[单选题]Recent studies have posed the question as to whether there is a link betwee
[单选题]Comparisons were drawn between the development of television in the 20th ce
[单选题]Comparisons were drawn between the development of television in the 20th ce
[单选题]Comparisons were drawn between the development of television in the 20th ce
[单选题]Comparisons were drawn between the development of television in the 20th ce
[单选题]Comparisons were drawn between the development of television in the 20th ce