单项选择题
A.an oil seal B.removing heat C.a gas seal D.cooling the piston
The figure that the volume of air at BDC is divided by ...
单项选择题The figure that the volume of air at BDC is divided by the volume of air at TDC is termed as（）.
A.ignition ratio B.power ratio C.compression ratio D.injection ratio
The external circumference of a pair of main bearing sh...
单项选择题The external circumference of a pair of main bearing shells is slightly larger than that of the bore of the housing which receives themThe difference is termed （）.
A.nip B.nap C.gap D.lip
单项选择题The external circumference of a pair of main bearing shells is slightly （） that of the bore of the housing which receives themWhat’s the meaning of “that” in the sentence above?
A.less than B.lighter than C.larger than D.smaller than
