99色精品-9色在线-99色在线-99色视频 国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

單項選擇題

()uses one or two high pressure pumps for all the cylinders with one more standby, while()have a separate high-pressure pump for each cylinder.

A.A common rail engine;conventional engines
B.A conventional engine;common rail engines
C.A marine diesel engine;most other engines
D.A two-stroke engine;four-stroke engines

微信掃碼免費(fèi)搜題