网址:http://m.1010jiajiao.com/timu3_id_391437[举报]
A.3∶1 B.1∶3 C.3∶2 D.2∶3
A.1︰1 B.1︰3?
C.3︰1 D.1︰2?
A.3∶1 B.1∶3 C.5∶2 D.4∶1