如病情进展，出现上腹压痛、反跳痛、肌紧张，移动性浊音(+)，此时最有价值的检查是

A．尿淀粉酶测定

B．血清淀粉酶测定

C．白细胞计数和分类

D．腹穿液性状及淀粉酶测定

E．血红蛋白和红细胞比值测定

The purpose of the requirements definition phase is to produce a clear, complete, consistent, and testable （） of the technical requirements for the software product. During the requirements definition phase, the requirements definition team uses an iterative process to expand a broad statement of the system requirements into a complete and detailed specification of each function that the software must perform and each （） that it must meet. The starting point is usually a set of high-level requirements from the （） that describe the project or problem. In either case, the requirements definition team formulates an overall concept for the system and then defines （） showing how the system will be operated, publishes the system and operations concept document, and conducts a system concept review(SCR). Following the SCR, the team derives （） requirements for the system from the high level requirements and the system and operations concept. Using structured or object-oriented analysis, the team specifies the software functions and algorithms needed to satisfy each detailed requirement.

The starting point is usually a set of high-level requirements from the （） that describe the project or problem.

A．producer

B．customer

C．programmer

D．analyser