For nearly  ten years，  the Unified Modeling Language  （UML） has been  the  industry standard  for  visualizing，  specifying，  constructing，  and  documenting  the   （  ）of  a software-intensive system. As the（  ）standard modeling language， the UML facilitates communication and reduces confusion among project （  ）. The recent standardization of UML 2.0 has further extended the language’s scope and viability. Its  inherent expressiveness allows  users  to （  ）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（  ）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.