单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. The application allows users to post comments to a page that can be viewed by other users. You add a SqlDataSource control named SqlDS. You write the following code segment：   01 private void SaveComment（）   02 {   03   string ipaddr；   04   05   SqlDS1.InsertParameters["IPAddress"].DefaultValue = ipaddr；   06   ...  07   SqlDS1.Insert（）；   08 }   You need to ensure that the IP Address of each user who posts a comment is captured alongwith the user’s comment.  Which code segment should you insert at line 04？（）

单项选择题 You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. All the content pages in the application use a single master page. The master page uses a static navigation menu to browse the site.  You need to ensure that the content pages can optionally replace the static navigation menu with their own menu controls.  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. The application has a mobile Web form that contains the following ObjectList control：   <mobile：ObjectList ID="ObjectListCtrl"  OnItemCommand="ObjectListCtrl_ItemCommand" Runat="server">   <Command Name="CmdDisplayDetails" Text="Details" />   <Command Name="CmdRemove" Text="Remove" />   </mobile：ObjectList>    You create an event handler named ObjectListCtrl_ItemCommand.  You need to ensure that the ObjectListCtrl_ItemCommand handler detects the selection of the CmdDisplayDetails item.  Which code segment should you write？（）