| 软件水平考试系统分析师易错题（2018/11/1） |
| 第1题：基于“学生-选课-课程”数据库中的三个关系：
S(S#，SNAME，SEX，AGE、，SC(S#，C#，GRADE、，CC#，CNAME，TEACHER) 若要求查找选修“数据库技术”这门课程的学生姓名和成绩，将使用关系( )。 A、S和SC B、SC和C C、S和C D、S,SC和C |
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| 第2题：下列磁盘调度算法中，( )体现了公平性?
A、先来先服务 B、最短寻道时间优先 C、电梯算法 D、单向扫描 |
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| 第3题：以下关于数据结构的基本概念的叙述中( )是错误的。
A、数据元素是数据的基本单位 B、数据项是有独立含义的数据最小的单位 C、数据结构概念包含的主要内容是数据的逻辑结构和数据的存储结构 D、数据的逻辑结构分为线性结构和非线性结构 |
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| 第4、5题：命题公式￢(P∨Q)←→(P∧Q)的合取范式为(4)，析取范式为(5)。
(4) A、(P∨Q)∧(￢P∨￢Q) B、(P∨￢Q)∧(￢P∨￢Q) C、(￢P∨Q)∧(P∨￢Q) D、(P∨Q)∧(￢P∨Q) (5) A、(P∧Q)∨(￢P∧Q) B、(￢P∧￢Q)∨(￢P∧Q) C、(P∧￢Q)∨(￢P∧Q) D、(P∧￢Q)∨(P∧Q) |
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| 第6、7、8、9、10题：In the following essay, each bland has four choices.Choose the best answer and write down on the answer sheet. With the implementation of (6) the so – called network has become a reality. The provision of such facilities is the most important part of the network requirements. However, 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 (7) interface between user(application)program, normally referred to ,as application processes, and the underlying communication services may be (8). For example, one computer may be a small single-user computer, while another may be a large (9) system. In the earlier days of computer communication, these issues meant that only closed communities of computers (that is, from the same manufacturer) could communicate with each other in a meaningful way. IBM’s systems NetworkArchitecture (SNA、andDEC’sDigital NetworkArchitectureDNA、are just two examples of communication software packages produced by manufacturers to allow their systems to be intercormected 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,(10) ,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 be placed into perspective with one another.
(6) A、communicationchannel B、protocols C、datachannel D、publiccommunication (7) A、database B、datarepresentation C、protocols D、datacommunication (8) A、same B、similar C、different D、dependent (9) A、multi-user B、client C、server D、full-user (10) A、DNA B、SNA C、theOSI D、theISO |
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