单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. When you access the application in a Web browser， you receive the following error message： "Service Unavailable".  You need to access the application successfully.  What should you do？（）

单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. You plan to capture the timing and performance information of the application.  You need to ensure that the information is accessible only when the user is logged on to the Web server and not on individual Web pages.  What should you add to the Web.config file？（）

多项选择题 You create a Microsoft ASP.NET AJAX application by using the Microsoft .NET Framework version 3.5.  A JavaScript code segment in the AJAX application does not exhibit the desired behavior. Microsoft Internet Explorer displays an error icon in the status bar but does not prompt you to debug the script.  You need to configure the Internet Explorer to prompt you to debug the script.  Which two actions should you perform？（）