下述哪项不是上消化道内镜检查适应证

A．急性胃、食管炎症，尤其是腐蚀性、坏死性炎症
B．消化道出血原因不明
C．上腹部有症状而X线检查阴性或疑有癌变但不能确诊者
D．X线发现溃疡或充盈缺损，性质不明
E．因下困难、吞咽疼痛及胸骨后烧灼感疑有"食管性胸痛"

For nearly ten years,the Unified Modeling Language (UML) has been the industry standard for visualizing,specifying,constructing,and documenting the(1)of a software-intensive system.As the(2)standard modeling language,the UML facilitates communication and reduces confusion among project(3).The recent standardization of UML 2.0 has further extended the language's scope and viability.Its inherent expressiveness allows users to(4)everything from enterprise information systems and distributed Web-based applications to real-time embedded systems. 　　

The UML is not limited to modeling software.In fact,it is expressive enough to model (5)systems,such as workflow in the legal system,the structure and behavior of a patient healthcare system,software engineering in aircraft combat systems,and the design of hardware. 　　

To understand the UML,you need to form a conceptual model of the language,and this requires learning three major elements:the UML's basic building blocks,the rules that dictate how those building blocks may be put together,and some common mechanisms that apply throughout the UML.

空白（2）处应选择（）

A.real

B.legal

C.defacto

D.illegal