(1)analysis emphasizes the drawing of pictorial system models to document and validate both existing and/or proposed systems. Ultimately, the system models become the (2)for designing and constructing an improved system. (3)  is such a technique. The emphasis in this technique is process-centered. Systems analysts draw a series of process models called (4).(5) is another such technique that integrates data and process concerns into constructs called objects.

空白（2）处应选择（）

A.image

B.picture

C.layout

D.blueprint

试述制定我国的资产评估准则的必要性。