Step 5: Size your Grid #3
Just do the same with the upper screen size "768-992 px (md)" and define it's size to 1. That means it will be displayed one next to another horizontally, taking the full screen size. You can obviously pick the sizes you want in the Properties tab depending on how you want to display it, this tutorial shows you the basics.
Finally, the next step will show how to center your content (your text) in your grid.