单项选择题 根据下图，假设路由器已经配置了默认配置，那么这个接口是（）。

多项选择题 Why do large OSPF networks use a hierarchical design?（）

单项选择题 A TCP/IP Transfer is diagrammed in the exhibit.A window size of three has been negotiated for this transfer. Which message will be returned from the receiver to the sender as part of this TCP/IP transfer?（）