单项选择题
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
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.
单项选择题 In a common rail engine, the fuel is injected into cylinders（）
单项选择题 In common rail engines, the fuel is（） before is injected into the cylinders.