第三章 Lecture4ComputerNetworks第四课计算机网络.pptVIP

What does a typical computer network include? ——A typical computer network includes host computers, nodes, terminal controllers, and terminals. What makes the providers obtain a wider variety of communication services through network? —— The increased capabilities of the networks allow providers to offer a wider variety of communication services through network. 2.Translate the following phrases and expressions. to allow the exchange of information between the users of different mainframes ——能够在不同主机的用户之间交换信息 be connected but fully retain their autonomy ——相互连接但完全保持独立 campus-wide networks ——校园范围内的网络 to offer a wider variety of communication services than the traditional voice services ——提供比传统语音服务更广泛的通信服务 be represented by continuous smoothly varying signals ——用连续平滑变化的信号表示 在网上共享硬件和软件资源 ——share hardware and software resources on the network 3.Match Column A with Column B. 4.Judge true or false according to the text. A typical network includes host computers, nodes, terminal controllers, and terminals.( ) A wide-area network is two or more computers directly linked within a small area such as a room or a building.( ) Networks can be either analog or digital.( ) We can exchange information through computer network, but because of its poor reliability, we should pay attention to the security factor.( ) 5. Translate the following sentences into Chinese, paying more attention to the uses of “as” clauses. Clearly, as the range of computer communication networks proliferate, computer to computer communication will expand rapidly and ultimately dominate the field of distributed systems. ——显然，随着计算机通信网络范围的扩散，机-机通信将迅速扩张并最终引领分布式系统领域。 As the inverting input is virtually at ground potential, the current which flows through R1 is equal to the input voltage Ui divided by R1. ——由于反接，输入端实际上是位于接地电位，通过R1的电流就等于输入电压Ui除以电阻R1 。 As the definition implies an ISDN is merely an enhancement to the telephone local loop that will allow both voice and data to be carried over