●具有6个顶点的连通图的广度优先生成树，其边数为 (53) 。

●若关键字是非负整数，快速排序、归并、堆排序和基数排序 (54) 最快。若要求辅助空间为O (1) ，应选 (55) 。

●多媒体计算机中的媒体信息是指 (56) ，多媒体技术的主要特性有 (57) 。目前音频卡具备的功能有 (58) 。在多媒体计算机中常用的图像输入设备是 (59) 。国际标准MPEG-2采用了分层的编码体系，提供了4种技术，它们是 (60) 。

●某种中继设备提供运输层及运输层以上各层之间的协议转换，这种中继设备是 (61) ，从OSI协议层次来看，用以实现不同网络间的地址翻译、协议转换和数据格式转换等功能的路由器属于 (62) 范畴，当采用数据报服务时，负责端到端的流量控制的是 (63) 。路由器的主要功能是 (64) ，下列接入方式中， (65) 不属于ISP的接入方式。

●Software designis a (66) process.It requires acertain (67) of flair on the partof the designer.Design can not be learned from a book.It must be practiced and learnt by experienceand study of existing systems.A well (68) software system is straightforward to implementand maintain，easily (69) and reliable.Badly (68) software systems，although theymay work are (70) to be expensive to maintain，difficult to test and unreliable.

●Basically,a(71)is a standalone process or a set of integrated processes that runs on a router or server to control the flow of(72)application traffic(73)through it.Typically,firewalls are(74)on the entry point to a public network such as the Internet.They could be considered traffic cops.The firewall's(75)is to ensure that all communication between an organization's network and the Internet conform. to the organization's security policies.