单选题 For nearly ten years, the Unified Modeling Language (UML) has been the industry standard for visualizing, specifying, constructing, and documenting the 19 of a software-intensive system. As the 20 standard modeling language, the UML facilitates communication and reduces confusion among project 21 . The recent standardization of UML 2.0 has further extended the language"s scope and viability. Its inherent expressiveness allows users to 22 everything from enterprise information systems and distributed Web-based applications to real-time embedded systems.
The UML is not limited to modeling software. In fact, it is expressive enough to model 23 systems, such as workflow in the legal system, the structure and behavior of a patient healthcare 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 requires learning three major elements: the UML"s basic building blocks, the rules that dictate how those building blocks may be put together, and some common mechanisms that apply throughout the UML.