（）是产生创新的基础和原料，任何领域的创新活动都要以该领域中的已有知识和成果为起点。

A.知识

B.思想

C.潜能

D.实践

As a project manager, you must formalize acceptance of the project scope and keep the project focused on the business need that it was undertaken to address. This should be done ______ .

A．at the beginning of the project

B．at the end of the project

C．when required by the business sponsor

D．after each phase of the project