配置WWW服务器是UNIX操作平台的重要工作之一，而Apach是目前应用最为广泛的Web服务器产品之一，(56)是Apache的主要配置文件。

 URL根目录与服务器本地目录之间的映射关系是通过指令(57)设定；指令Server- Admin的作用是(58)：而设置index.html或default.html为目录下默认文档的指令是(59)；如果允许以"http：//www.xxx.edu.cn/～username"方式访问用户的个人主页，必须通过(60)指令设置个人主页文档所在的目录。

(159)

(158)

(157)

For each blank, choose the best answer from the four choices and write down on the answer sheet.

(71)is a one-way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string.

(72)is a protocol that most USENET machines now use it to allow news articles to propagate from one machine to another over a reliable connection.

(73)is an approach preferred by cable TV providers. In this solution the fiber terminates at an optoelectrical converter and the final segment is a shared coaxial cable.

(74)is a device used to connect two separate network that use different communication protocol.

(75)is a digital-to-digital polar encoding method in which the signal level is always either positive or negative.

(156)

(153)

(154)

(152)

帧中继网的虚电路建立在()

(151)