若5:7的前项加上10,要使比值不变;后项加上请选择CBA;S'f1H,{,\/y-B;{/E/Y5x8C8n,F
A.7/Y5x8C8n,F
B.10/Y5x8C8n,F
C.14/Y5x8C8n,F
D.5/Y5x8C8n,F