甲数是乙数的1/5,乙数和甲数的比是请选择ABC'p)C4n3O5n5h9|:d6u(?2i3]5s*I.X1M
A.1:5(?2i3]5s*I.X1M
B.1:6(?2i3]5s*I.X1M
C.5:1(?2i3]5s*I.X1M