单项选择题
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）.
空白（2）处应选择（）
A.workflow engines B.processes C.workflow threads D.tasks
单项选择题 空白（1）处应选择（）
