单项选择题
A.at high speed and full load B.at low speed and part load C.when heavy fuel oil is used at sea D.when the ships run long distance
A common rail engine has only one or two high pressure ...
单项选择题A common rail engine has only one or two high pressure pumps in operation at the same（）time, and the injection into each cylinder.
A.can’t be controlled very precisely B.can’t be controlled as flexibly as the separate pump system C.can be controlled as flexibly as the separate pump system D.can be controlled more precisely and flexibly
（）uses one or two high pressure pumps for all the cylin...
单项选择题（）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
In a common rail engine, the fuel is injected into cyli...
单项选择题In a common rail engine, the fuel is injected into cylinders（）
A.by injection pumps B.at a time decided by the injection pump timing C.by a signal opening the magnetic valves D.at a time decided by the cam directly
