The Internet is an open system, and most information is available to everyone. It is very important to add (74) to existing system for protecting the secret information.(74)

A． Web pages

B． modem

C． security

D． network

[单选题]The Internet is an open system，and most information is available to everyone．It is very important to add(74)to existing system for protecting the secret information．A．Web pagesB．modemC．securityD．network

[单选题]The Internet is an open system, and most information is available to everyone. It is very important to add ______ to existing system for protecting the secret information.A．web pagesB．modemC．securityD．NetworkA．B．C．D．

[单选题]The Internet is an open system，and most information is available to everyon

[主观题]The Internet is a () system of interconnected computer networks that use the standard Internet protocol suits(TCP/IP) to serve several billion users worldwide。A．global B．regional C．local D．national

[单选题]OSI(Open System Interconnection)安全体系方案X.800将安全服务定义为通信开放系统协议层提供的服务，用来保证系统或数据传输有足够的安全性。X.800定义了5类可选的安全服务。下列相关的选项中不属于这5类安全服务的是 (63) 。(63) A．数据保密性B．认证C．访问控制D．数据压缩

[单选题]OSI (Open System Interconnection)安全体系方案X.800将安全性攻击分为两类，即被动攻击和主动攻击。主动攻击包括篡改数据流或伪造数据流，这种攻击试图改变系统资源或影响系统运行。下列攻击方式中不属于主动攻击的为______。A．伪装B．消息泄露C．重放D．拒绝服务

[单选题]The Internet is a （）system of interconnected computer networks that use the

[单选题]OSI(Open System Interconnection)安全体系方案X.800将安全性攻击分为两类，即被动攻击和主动攻击。主动攻击包括篡改数据流或伪造数据流，这种攻击试图改变系统资源或影响系统运行。下列攻击方式中不属于主动攻击的是______。A．伪装B．消息泄漏C．重放D．拒绝服务

[单选题]OSI(Open System Interconneetion)安全体系方案X.800将安全性攻击分为2类，即被动攻击和主动攻击。主动攻击包括篡改数据流或伪造数据流，这种攻击试图改变系统资源或影响系统运行。下列攻击方式中不属于主动攻击的为______。A．伪装B．消息泄漏C．重放D．拒绝服务

[单选题]OSI(Open System Interconnection)安全体系方案X.800将安全服务定义为通信开放系统协议层提供的服务，用来保证系统或数据传输有足够的安全性。X.800定义了5类可选的安全服务。下列相关的选项中不属于这5类安全服务的是______。A．数据保密性B．访问控制C．认证D．数据压缩