How to represent Line Break or new line in silverlight textBox

I am having hard time to match Special characters set in Silverlight. I only on the following:

To represent a LineBreak in Silverlight TextBlock:

use : > lineBreak <

But What do I use to represent a New Line or LineBreak In Silverlight TextBox??

Example : I want this one line mag : This is line one. This is line two

into this :

This is line one. Это строка 2.

кажется, что \ r \ n не работает. Это первая строка \ r \ n