单项选择题
A.送给子网Y1 B.同时送给子网Y1和Y2 C.送给子网Y2 D.丢弃
A.六 B.七 C.八 D.十六
A.196.28.128.0/21 B.196.28.128.0/22 C.196.28.130.0/22 D.196.28.132.0/23