100BASE-FX采用4B/5B和NRZ-I编码，这种编码方式的效率为（）。（）

某网站向CA申请了数字证书，用户通过______来验证网站的真伪。

国家信息化建设的信息化政策法规体系包括信息技术发展政策、______、电子政务发展政策、信息化法规建设等四个方面。

网络设备管理是网络资源管理的重要内容。在网络设备中，网关属于______。

企业信息资源管理不是把资源整合起来就行了，而是需要一个有效的信息资源管理体系，其中最为关键的是______。

网络管理包含5部分内容：______、网络设备和应用配置管理、网络利用和计费管理、网络设备和应用故障管理以及网络安全管理。

下列网络互连设备中，属于物理层的是______。

操作系统是裸机上的第一层软件，其他系统软件(如(1)等)和应用软件都是建立在操作系统基础上的。下图①②③分别表示(2)。

(1)

IT系统管理工作可以按照一定的标准进行分类。在按系统类型的分类中，______作为企业的基础架构，是其他方面的核心支持平台，包括广域网、远程拨号系统等。

Why is (1) fun?What de lights may itS practitioner expect as his reward? First is the sheer joy of making things. As the child delights in his mud pie, so the adult enjoys building things, especially things of his own design. Second is the pleasure of making things that are useful to other people. Third is the fascination of fashioning complex puzzle-like objects of interlocking moving parts and watching them work in subtle cycles, playing out the consequences of principles built in from the beginning. Fourth is the joy of always learning, which springs from the (2) nature of the task. In one way or another the problem is ever new, and its solver learns something: sometimes (3), sometimes theoretical, and sometimes both. Finally, there is the delight of working in such a tractable medium. The (4), like the poet, works only slightly removed from pure thought-stuff. Few media of creation are so flexible, so easy to polish and rework, so readily capable of realizing grand conceptual structures.

Yet the program (5), unlike the poet's words, is real in the sense that it moves and works, producing visible outputs separate from the construct itself. It prints results, draws pictures, produces sounds, moves arms. Programming then is fun because it gratifies creative longings built deep within us and delights sensibilities we have in common with all men.

(1)