单选题防火墙通常分为内网、外网和DMZ三个区域，按照受保护程度，从低到高正确的排列次序为 。

单选题POP3服务默认的TCP端口号是______。

单选题将网址转换为IP地址要用( )协议。

单选题下面可提供安全电子邮件服务的是_______。

单选题在网络系统设计时，不可能使所有设计目标都能达到最优，下列措施中较为合理的是（）。

单选题若无向图G有n个顶点e条边，则G采用邻接矩阵存储时，矩阵的大小为( )。

单选题在对于现有系统进行分析时，_______方法是错误的。

单选题以下关于网络攻击的叙述中，错误的是______。

单选题软件可维护性是指一个系统在特定的时间间隔内可以正常进行维护活动的概率。用MTTF和MTTR分别表示无故障时间和平均修复时间，则软件可维护性计算公式为（）

单选题在ISOIEC软件质量模型中，可移植性是指与软件可从某环境移到另一环境的能力有关的一组属性，其子特性不包括 。

单选题在CPU中，用（）给出将要执行的下一条指令在内存中的地址。

单选题设关系模式RU,F, U={A1，A2，A3，A4}，函数依赖集F={A1→A2，A1→A3 ，A2→A4}，关系R的候选码是作答此空。下列结论错误的是 。

单选题某单位网站首页被恶意篡改，应部署( )设备阻止恶意攻击。

单选题We initially described SOA without mentioning Web s ervices, and vice versA. This is because they are ortho gonal: service-orientation is an architectural () whil e Web services are an implementation ( ).The two can be used together, and they frequently are, but they are not mutually dependent.For example, although it is widely considered to be a distributed-computing solution,SOA can be applied to advantage in a single system,where services might be individual processes with well-defined ( ) that communicate using local channels,or in a self-contained cluster, where they might communicate across a high -speed interconnect.Similarly, while Web services are(回答此处 ) as the basis for a service-oriented environment, there is nothing in their definition that requires them to embody the SOA p rinciples. While( )is often held up as a key characte ristic of Web services,there is no technical reason that they should be stateless-that would be a design choi ce of the developerwhich may be dictated by the arc hitectural style of the environment in which the servic e is intended to participate.

单选题We initially described SOA without mentioning Web s ervices, and vice versA. This is because they are ortho gonal: service-orientation is an architectural (回答此处) whil e Web services are an implementation ( ).The two can be used together, and they frequently are, but they are not mutually dependent.For example, although it is widely considered to be a distributed-computing solution,SOA can be applied to advantage in a single system,where services might be individual processes with well-defined ( ) that communicate using local channels,or in a self-contained cluster, where they might communicate across a high -speed interconnect.Similarly, while Web services are( ) as the basis for a service-oriented environment, there is nothing in their definition that requires them to embody the SOA p rinciples. While( )is often held up as a key characte ristic of Web services,there is no technical reason that they should be stateless-that would be a design choi ce of the developerwhich may be dictated by the arc hitectural style of the environment in which the servic e is intended to participate.

单选题在地址栏中输入www.abc.com，浏览器默认的应用层协议是（）。

单选题Telnet协议是一种( )的远程登录协议。

单选题M公司将其开发的某软件产品注册商标为S，为确保公司在市场竞争中占据地位，M公司对员工进行了保密约束，此情形下，该公司不享有( )。