史学家陈锋、张建民主编的《中国经济史纲》指出中国在宋代至清代的历史进程中有过三次商业革命，“第一次是宋代商业革命，第二次是明清商业革命，第三次是近代商业革命……”下列符合“第一次商业革命”的是（   ）

A．白银成为普遍流通的货币

B．商业活动的群体——商帮形成

C．远洋贸易开始使用指南针

D．烟草等经济作物开始传入

An architectural style defines as a family of such systems in terms of a (1) of structural organization. More specifically, an architectural style defines a vocabulary of (2) and connector types, and a set of (3) on how they can be combined. For many styles there may also exist one or more (4) that specify how to determine a system's overall properties from the properties of its parts. Many of architectural styles have been developed over the years. The best-known examples of (5) architectures are programs written in the Unix shell.

空白（4）处应选择（）

A.semantic models

B.weak entities

C.data schemas

D.business models