The (29) is a general description of the architecture of a workflow management system used by the WFMC, in which the main components and the associated interfaces are summarized. The workflow enactment service is the heart of a workflow system which consists of several (30) 。

30（）

A. workflow engines

B. processes

C. workflow threads

D. tasks

在绘制亲和图时，用于贯彻方针目标时常用的语言文字资料收集方法是( )。

A．回忆法

B．文献调查法

C．头脑风暴法

D．直接观察法