外科急腹症常见的特点是（）

A.先发热后腹痛

B.腹痛部位较明确

C.腹痛程度较重

D.腹膜刺激征明显

E.腹式呼吸正常

（71）analysis emphasizes the drawing of pictorial system models to document and validate both existing and/or proposed systems. Ultimately, the system models become the （72）for designing and constructing an improved system. （73）is such a technique. The emphasis in this technique is process-centered. Systems analysts draw a series of process models called （74） . （75） is another such technique that integrates data and process concerns into constructs called objects.

（72）处填（）。

A．image

B．picture

C． layout

D．blueprint