如下图所示，一容器的底面有一平面镜，容器中盛有水，一束光线与水面的夹角为α，试画出入射光线进入水中，经平面镜反射又射入空气中的光线传播路线。
系统测试中应遵循的一条原则是：测试工作应该由以下人员来承担( )。
A．原程序作者
B．专门的测试人员
C．系统设计人员
D．用户
WebSQL is a SQL-like (26) language for extracting information from the web. Its capabilities for performing navigation of web (27) make it a useful tool for automating several web-related tasks that require the systematic processing of either ail the links in a (28) , all the pages that can be reached from a given URL through (29) that match a’ pattern, or a combination of both. WebSQL also provides transparent access to index servers that can be queried via the Common (30) Interface.
A．paths
B．chips
C．tools
D．directories
