For neady ten years，the Unified Modeling Language(UML)has been the industry standardfor visualizing，specifying，constructing，and documenting the【S1】of a software-intensivesystem．As the【S2】standard modeling language，the UML facilitates communication andreduces confusion among project【S3】．The recent standardization of UML 2．0 has furtherextended the language’s scope and viability．Its inherent expressiveness allows users to【S4】everything from enterprise information systems and distributed Web·-based applications to real-timeembedded systems．The UML is not limited to modeling software．In fact，it is expressive enough to model【S5】systems，such as workflow in the legal system，the structure and behavior. of a patienthealthcare system，software engineering in aircraft combat systems，and the design of hardware．To understand the UML，you need to form. a conceptual model of the language，and this re—quires learning three major elements：the UML's basic building blocks，the rules that dictate howthose building blocks may be put together，and some common mechanisms that apply throughout theUML．

【S1】

A．classes

B．components

C．sequences

D．artifacts

D解析：近十年來，統一建模語言(uML)已經成為工業標準，它可用來可視化、規范化說明、構建以及文檔化軟件密集系統中的開發制品。作為事實上的工業標準，UML能夠方便項目相關人員的溝通并減少理解上的二義問題。uML 2．0標準擴寬了該語言的應用范圍，它所具有的表達能力能夠讓用戶對企業信息系統、分布式Web系統和嵌入式實時系統進行建模。uML不僅能夠對軟件系統進行建模，實際上，它具有足夠的能力去對法律系統中的工作流、病人監護系統中的結構和行為、飛行戰斗系統和硬件系統進行建模。為了理解UML，需要具備該語言的概念