You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application that displays an image.
You need to ensure that users can stretch and scale the image. 
Which control should you use?（）

You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. 
You need to ensure that users can view content in a book-reading format that displays two pages at a time. 
Which control should you use?（）

You use Microsoft .NET Framework 4 to create a Windows Forms application.
You write the following code segment. (Line numbers are included for reference only.)
01sealed class FormSettings :

You need to ensure that the first time each user opens the application, a text field displays the following message: "Please enter your setting."
Which code segment should you insert at line 03?（）

You upgrade a Windows Forms application to Microsoft .NET Framework 4. The application was developed
by using a previous version of the .NET Framework. The application uses the Code 
Access Security (CAS) policy for file access. 
When the application is executed, you receive the following exception:  
"NotSupportedException: This method uses CAS policy, which has been obsoleted by the .NET Framework." 
You need to resolve the error. 
What should you do?（）