工程建设合同是( )。

A．主合同

B．从合同

C．诺成性合同

D．实践性合同

E．无偿合同

Representations of software architecture are an enabler for communication between all parties (stakeholders) interested in the development of a computer-based system. An architectural style defines as a family of suchsystems in terms of a ______ of structural organization. More specifically, each ______ describes a systemcategory that encompasses: (1) a set of components (e.g., a database, computational modules) that perform afunction required by a system, (2) a set of ______ that enable "communication, coordination andcooperation" among components, (3)______ that define how components can be integrated to form thesystem, and (4) semantic models that enable a designer to understand the overall properties of a system byanalyzing the known ______ of its constituent parts.

A. interfaces B. properties C. robustness D. Inter-operation