You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. 
You create a game where a ball drops from the top to the bottom of a window.
You plan to create a single animation for the game.
You need to ensure that the animation shows the ball bounce.
What should you do?（）

You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. The
application contains a form named frmMain that contains a button named btnSave. 
You create a ProgressBar control named saveProgress. Initially, saveProgress is not displayed on frmMain. 
When a user clicks btnSave, you have the following requirements: 
saveProgress is slightly visible after 0.2 seconds 
saveProgress is fully visible after 1 second  
You need to declare the corresponding storyboard.  
You write the following code fragment. (Line numbers are included for reference only.)  

Which code fragment should you insert at line 02 to complete the declaration?（）