单项选择题
A.iUser B.users C.public D.anonymous
A.route rip B.ip routing C.rip 172.16.0.0 D.network 172.16.0.0
A.36.28.0.0/17 B.36.28.1.0/17 C.36.28.128.0/18 D.36.28.192.0/18