单项选择题
A.50%,50% B.40%,60% C.60%,40% D.45%,55% E.A、B、C、D都不正确
A.6% B.8% C.15.5% D.25.5% E.A、B、C、D都不正确
A.0.7 B.0.75 C.0.8 D.0.85 E.A、B、C、D均不正确