A.-5B.5C.10D.20
A.26.10 B.28.56 C.32.78 D.35.23
A.13.5% B.15.6% C.15% D.16.8%
A.A方案 B.B、C两方案均可 C.C方案 D.A、B两方案均可
A.4~5 B.5~6 C.6~7 D.7~8