You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. 
You write the following code fragment. （Line numbers are included for reference only.） 
01  02 ID="rfValidator1" runat="server" 
03 Display="Dynamic" ControlToValidate="TextBox1" 
04 
05 > 
06 
07  
08 
09 
10 ID="ValidationSummary1" runat="server" /> 
You need to ensure that the error message displayed in the validation control is also displayed in the validation summary list. 
What should you do？（）

You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5. 
You create a custom-templated server control. 
| English | Chinese | Japan | Korean | - 112 - Test Information Co.， Ltd. All rights reserved. You need to ensure that the child controls of the server control are uniquely identified within thecontrol hierarchy of the page. 
Which interface should you implement？ （）