下面哪些协议支持可变长度子网掩码和路由聚合?()。
A.RIP v1
B.RIP v2
C.OSPF
D.VTP
参考答案:B, C
句型转换
小题1:Daming can play football. ( 改为否定句)
小题2:Her sister can sing English songs. ( 改为疑问句)
小题3:Can she play the piano? ( 作肯定回答)
小题4:Can you speak English? ( 作否定回答)
小题5:Can your mother ride a horse? (改为陈述句)