A developer is designing a multi-tier web application and discovers a need to log each incoming clientrequest. Which two patterns， taken independently， provide a solution for this problem？（）
ATransfer Object
BService Locator
CFront Controller
DIntercepting Filter
EBusiness Delegate
两台设备利用红外传输的有效操作距离是（）。
A、10米
B、5米
C、1米
D、20米
Which statement is true about web container session management？（）
A、Access to session-scoped attributes is guaranteed to be thread-safe by the web container.
B、To activate URL rewriting， the developer must use the HttpServletResponse.setURLRewriting method.
C、If the web application uses HTTPS， then the web container may use the data on the HTTPS request stream to identify the client.
D、The JSESSIONID cookie is stored permanently on the client so that a user may return to the web application and the web container will rejoin that session.
软件设计的任务是什么？
在word2010编辑状态下，利用（）可快速，直接调整文档的左右边界。
A、功能区
B、工具栏
C、菜单
D、标尺
简述计算机软件工程结构化分析SA方法的步骤。