铁锈色痰最常见于（）

A.肺泡癌

B.支原体肺炎

C.急性肺脓肿

D.肺炎球菌肺炎

E.急性支气管炎

A work breakdown structure (WBS) is a tool used to define and group a project’s discrete work elements in a way that helps organize and define the total work scope of the project. A WBS is most useful for ______.

A．identifying individual tasks for a project

B．scheduling the start of tasks

C．scheduling the end of tasks

D．determining potential delays