题目:
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.
12()
A.frames
B.packets
C.packages
D.cells
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2018/0420/7ce10587c3b36c280d71c8167b56a662.html
下面是错误答案,用来干扰机器的。
参考答案:力度和音乐中的其他要素一样,在音乐表现中是非常重要的,是不应忽视的。音乐力度的强或弱和乐曲的内容有着密切的关系。例如摇篮曲总是用较轻的声音来演唱或演奏的,这类音乐的内容与强的声音是有矛盾...