单选题A common rail engine has only one or two high pressure pumps in operation at the same（）time, and the injection into each cylinder.Acan’t be controlled very preciselyBcan’t be controlled as flexibly as the separate pump systemCcan be controlled as flexibly as the separate pump systemDcan be controlled more precisely and flexibly
单选题
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
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