The (1) 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 (2) . In a workflow system, a process is specified using the process definition tool. Usually, processes are defined in terms of a (3) , which consists of (4) indicated using a circle, and (5) shown as a rectangle. These two components can be linked by means of a directed arc.

2（）

A．tasks

B．processes

C．workflow threads

D．workflow engines

CT薄层扫描示右主支气管内壁结节样软组织密度影，局部管腔变窄，右下肺肺窗示片絮状稍高密度影，边缘欠清。可能的诊断为

A．卡波济(Kaposi)肉瘤

B．支气管腺瘤

C．中央型错构瘤

D．早期周围型肺癌

E．早期中央型肺癌