A system's architecture is a representation of a system in which there is a mapping of (1) onto hardware and software components, a mapping of the (2) onto the hardware architecture, and a concem for the human interaction with these components. That is, system architecture is concerned with a total system, including hardware, software, and humans. Software architectural structures can be divided into three major categories, depending on the broad nature of the elements they show.1) (3) embody decisions as a set of code or data units that have to be constructed or procured. 2) (4) embody decisions as to how the system is to be structured as set of elements that have runtime behavior and interactions. 3) (5) embody decisions as to how the system will relate to nonsoftware structures in its environment (such as CPUs, file systems, networks, development teams, etc. ).
空白（1）处应选择（）
A.attributes
B.constraint
C.functionality
D.Requirements
参考答案：C
解析：系统架构是一个系统的一种表示，包含了功能到软硬件构件的映射、软件架构到硬件架构的映射以及对于这些组件人机交互的关注。也就是说，系统架构关注于整个系统，包括硬件、软件和使用者。软件架构结构根据其所展示元素的广义性质，可以被分为三个主要类别。①模块结构将决策体现为一组需要被构建或采购的代码或数据单元。②构件连接器结构将决策体现为系统如何被结构化为一组具有运行时行为和交互的元素。③分配结构将决策体现为系统如何在其环境中关联到非软件结构，如CPU、文件系统、网络、开发团队等。