在局域网中经常用HUB为中心组建网络。这种网络中某条线路或者节点发生故障时，其他线路或者节点(48)。

(82)

TCP means it is on the(74)layer and IP means it is on the(75)layer.

The(72)turns the source file into an object file and the(73)turns the object file into an executable file.

(80)

()is the 4th layer of the OSI reference model responsible for reliable network communication between end nodes.

The purpose of the(73)is to provide fully integrated analog services to users.

As computers evolve, they have become Smaller and smaller, while speed and(66)have increased tremendously.

(75)

(74)

面向对象的系统中，对象是基本的运行实体。对象既包括(31)，亦称数据，也包括作用于数据上的操作，亦称(32)。对象之间可以进行通信：一个对象可以向其它对象发送消息，其中包含要求接收这执行的操作；接收到消息的对象解释消息再予以响应，这种通信机制称为(33)。不同的对象受到统一消息可以产生不同的响应结果，这一现象称为(34)。