一个比的前项是2,如果前项增加8.要使比值不变,后项应扩大几倍请选择ABC-V9b0V5n2?/U/u,G0t5B+Y5a2@
A.2/u,G0t5B+Y5a2@
B.4/u,G0t5B+Y5a2@
C.5/u,G0t5B+Y5a2@