单项选择题
A.0.981,0.991,改进了比重环结构 B.0.991,1.010,取消了比重环 C.0.961,0.981,采用独立供油泵 D.0.961,1.000,取消了比重环
A.仅①正确 B.①、②正确 C.①、③正确 D.①、②、③都正确
A.仅①正确 B.②和③正确 C.①和②正确 D.①、②、③都正确