单选题校园网连接运营商的IP地址为202.117.113.3/30，本地网关的地址为192.168.1.254/24，如果本地计算机采用动态地址分配，在下图中应如何配置?______。
单选题若对关系R(A，B，C，D)、S(C，D，E)进行π1,2,3,4,7(σ3=5∧4=6(R×S))运算，则该关系代数表达式与______是等价的。A．RSB．σ3=5∧4=6(π1,2,3,4,7(R×S))C．πA,B,C,D,E(R×S)D．π1,2,3,4,7(σ3=5(R)×σ4=6(S))
单选题浏览器的功能有 (18) 。 ①向WWW系统发出浏览某个资源(URL)的请求 ②接收该信息资源 ③把该页显示在浏览器窗口上 ④构成讯问其它资源的接口
单选题用户程序通过 (7) 向操作系统提出使用外部设备的要求。A) 服务器 B) shell命令 C) 系统调用 D) I/O调用命令
单选题在常用的调度算法中，在进行 (27) 时，运行时间短的进程只需经过前面几级队列即可得到结果而运行时间较长的进程在进入低级就绪队列后能得到较长的时间片。
单选题关系模式R{A, B, C}, {AC-B, B-C}的候选码之一是（ ）;由于该模式存在主属性对码的部分函数依赖，其规范化程度最高属于（ ）
单选题软件开发的结构化生命周期方法将软件生命周期划分成
________
几个阶段。
单选题非关系模型中数据结构的基本单位是 (36) 。
单选题以下程序设计语言中，______更适合用来进行动态网页处理。
单选题诊疗科、医师和患者的 E-R 图如下所示，图中* *、* 1 分别表示多对多、1 对多的联系：
各实体对应的关系模式如下，其中带实下划线的表示主键，虚下划线的表示外键。
诊疗科（诊疗科代码，诊疗科名称）
医师（医师代码，医师姓名，诊疗科代码）
患者（患者编号，患者姓名）
若关系诊疗科和医师进行自然连接运算，其结果集为 （30） 元关系。医师和患者之间的治疗观察关系模式的主键是 （31） 。
单选题查找时间是______；光盘可以极大地提高______；微型计算机常配的滚筒式绘图机中______；与激光打印机有关的概念是______；阅读条码的硬件设备是______。
单选题数据库应用系统中通常会将标准编码构建成字典表，包含代码和名称项，如民族（民族代码，民族名称），针对这类表，为提高查询性能，应采用的优化方式是 （56） 。
单选题《中华人民共和国计算机信息网络国际联网管理暂行规定》规定：从事国际联网经营活动的和从事非经营活动的接入单位必须具备下列条件： (54) 。 (1) 是依法设立的企业法人或者事业法人 (2) 具有相应的计算机信息网络、装备以及相应的技术人员和管理人员 (3) 具有健全的安全保密管理制度和技术保护措施 (4) 符合法律和国务院规定的其他条件
单选题 当某程序执行时，利用重定位存储管理方式来访问内存，是将{{U}} {{U}}
22 {{/U}} {{/U}}相加得到{{U}} {{U}} 23 {{/U}}
{{/U}}来进行访问的。
单选题 (49) 的发展在80年代末至90年代中出现了一个高潮，UML就是其产物。
单选题某系统中有四种互斥资源R1、R2、R3 和R4，可用资源数分别为3、5、6 和8。假设在T0 时刻有P1、P2、P3 和P4 四个进程，并且这些进程对资源的最大需求量和已分配资源数如下表所示，那么在T0 时刻系统中R1、R2、R3 和R4 的剩余资源数分别为（22） 。如果从T0 时刻开始进程按 （23） 顺序逐个调度执行，那么系统状态是安全的。
单选题One of the functions of the (71) is to store the applications programs or the various secondaries. The (72) may have similar or dissimilar functions. The same control code received from two different, secondaries may warrant two different actions on the part of the host computer. If the system so requires, the host computer must also provide (73) for the centralized data and the software for database management. Data information is normally stored in auxiliary memories to which the computer has ready access. The (74) peripherals connected to the host computer allow for human entry and intervention. As needs change, application programs may require additions, deletions, or changes. Data link problems also arise which are (75) the range of the computer's programmed capabilities. In such cases, human entry is required to make the necessary changes to resolve the existing problems.
单选题Typically, these are concern with the establishment of (66) the network and with the control of the flow of messages across this channel. The provision of such facilities is only part of the network requirements, however, since in many applications the communicating computers may be of different types. This means that they may use different programming languages and, more importantly, different forms of (67) interface between user(application)program, normally referred to, as application processes or APs, and the underlying communication services may be (68) For example, one computer may be a small single -user computer, while another may be a large (69) system. In the earlier days of computer communication, these issues meantthat only closed communities of computers ( that is, from the same manufacturer) could communicate with each other in a meaningful way. IBM’s Systems Network. Architecture (SNA) and DEC's Digital Network Architecture (DNA) are just two examples of Communication software packages produced by manufacturers to allow their systems to be int erconnected together. These proprietary packages, however, of which there am still many inexistence, do not address the problem of universal interconnect ability, or open systems interconnection. In an attempt to alleviate this problem, (70) , in the late 1970s, formulated a reference model to provide a common basis ( or the coordination of standards developments and to allow existing and evolving standards activities to beplaced into perspective with one another.