情境分析

以下是几位同学在日常生活中的一些表现和存在的问题,请你运用所学知识分析他们的表现,帮助他们解决存在的问题。

情境一:期中考试试卷发下来后,小刚发现考得不理想,将试卷撕碎,再也无心听课。

情境二:文文刚上初二,最近一段时间她很渴望跟同学们交往,却又感到孤独,不愿与人交往,这让她十分苦闷。

Networks can be interconnected by different devices. In the physical layer, networks can be connected by (11) or hubs, which just move the bits from one network to an identical network. One layer up we find bridges and switches, which operate at data link layer. They can accept (12) ,examine the MAC address, and forward the frames to a different network while doing minor protocol translation in the process. In the network layer, we have routers that can connect two networks. If two networks have (13) network layer, the router may be able to translate between the packer formats. In the transport layer we find transport gateway, which can interface between two transport connections. Finally, in the application layer, application gateways translate message (14) . As an example, gateways between Internet e-mail and X.400 e-mail must (15) the e-mail message and change various header fields.

13（）

A.special

B.dependent

C.similar

D.dissimilar