单项选择题
A.Lower fuel consumption
B.Better balanced cylinder power
C.A shorter overhaul period
D.Less smoke emission
单项选择题 If a camshaft-less engine has a normal injection pressure at rated speed, the injection pressure will be at slow speed（）
单项选择题 If a cam-controlled engine has a normal injection pressure at rated speed,the injection pressure will be（）at slow speed.
单项选择题 The main purpose of changing main engine to electronic controlled is not to（）