单项选择题
A.A→D→B→C B.C→B→D→A C.C→A×B→B D.C→A×B→B→D
A.41.46% B.42.52% C.35.84% D.33.97%
A.A1B1C2D2 B.A2B2C1D1 C.A2B1C2D2 D.A1B2C1D2