（4）处应填（）。

A．P(S3)和V(S4)V(S5)
B．P(S3)和P(S4)P(S5)
C．V(S3)和V(S4)V(S5)
D．V(S3)和P(S4)P(S5)

[说明]

Linux系统有其独特的文件系统ext2，文件系统包括了文件的组织结构、处理文件的数据结构及操作文件的方法。可通过命令获取系统及磁盘分区状态信息，并能对其进行管理。

(44) 描述了一类软件架构的特征，它独立于实际问题，强调软件系统中通用的组织结构选择。垃圾回收机制是Java语言管理内存资源时常用的一种 (45) 。

[说明]

Linux系统有其独特的文件系统ext2，文件系统包括了文件的组织结构、处理文件的数据结构及操作文件的方法。可通过命令获取系统及磁盘分区状态信息，并能对其进行管理。

Information systems design is defined as those tasks that focus on the specification of a detailed computer-based solution. Typically, there are four systems design tasks for in-house development.

1) The first task is to specify (71) ,which defines the technologies to be used by one, more, or all information systems in terms of their data, processes, interfaces, and network components. This task is accomplished by analyzing the data models and process models that are initially created during requirements analys16.

2) The next systems design task is to develop the (72) . The purpose of this task is to prepare technical design specifications for a database that will be adaptable to future requirements and expansion.

3) Once the database prototype has been built, the systems designer can work closely with system users to develop input, output and dialogue specifications. The (73) must be specified to ensure that the outputs are not lost, misrouted, misused, or incomplete.

4) The fourth design task involves packaging all the specifications from the previous design tasks into a set of specifications that will guide the (74) activities during the following phases of the systems development methodology.

Finally, we should (75) and update the project plan accordingly. The key deliverable should include a detailed plan for the construction phase that should follow.

Information systems design is defined as those tasks that focus on the specification of a detailed computer-based solution. Typically, there are four systems design tasks for in-house development.

1) The first task is to specify (71) ,which defines the technologies to be used by one, more, or all information systems in terms of their data, processes, interfaces, and network components. This task is accomplished by analyzing the data models and process models that are initially created during requirements analys16.

2) The next systems design task is to develop the (72) . The purpose of this task is to prepare technical design specifications for a database that will be adaptable to future requirements and expansion.

3) Once the database prototype has been built, the systems designer can work closely with system users to develop input, output and dialogue specifications. The (73) must be specified to ensure that the outputs are not lost, misrouted, misused, or incomplete.

4) The fourth design task involves packaging all the specifications from the previous design tasks into a set of specifications that will guide the (74) activities during the following phases of the systems development methodology.

Finally, we should (75) and update the project plan accordingly. The key deliverable should include a detailed plan for the construction phase that should follow.

【说明】

某企业欲构建局域网，考虑到企业的很多业务依托于网络，要求企业内部用户能够高速的访问企业服务器，并且对网络的可靠性要求很高。因此，在网络的设计中，要考虑网络的冗余性，不能因为单点故障引起整个网络的瘫痪。

某网络公司根据企业需求，将网络拓扑结构设计为双核心来进行负载均衡，当其中一个核心交换机出现故障时，数据能够转换到另一台交换机上，起到冗余备份的作用。该公司给出的网络拓扑如图1-1所示。

某企业工程项目管理数据库的部分关系模式如下图所示，其中带实下划线的表示主键，虚下划线的表示外键

其中供应关系是（5）的联系。若一个工程项目可以有多个员工参加，每个员工可以参加多个项目，则项目和员工之间是（6）联系。对项目和员工关系进行设计时，（7）设计成一个独立的关系模式。