单项选择题
A.dozens B.parcels C.bundles D.gallons
The piston crown employs the usual jet-shaker principle...
单项选择题The piston crown employs the usual jet-shaker principle with an arrangement of cooling bores in the crown so that the surface temperatures of the crown are moderate with a very even distribution（）
A.water cooling B.oil cooling C.air cooling D.combined cooling
The development goals for a large marine engine are man...
单项选择题The development goals for a large marine engine are many often interact and in some cases even with each other（）
A.conflict B.accord C.harmonize D.struggle
The key feature of the Sulzer RT-flex system is that it...
单项选择题The key feature of the Sulzer RT-flex system is that it gives complete freedom in the and operation of fuel injection and exhaust valve actuation（）
A.metering B.control C.using D.timing
