<div class = "row">
<div class = "center-block" style = "width:200px; background-color:#ccc;">
This is an example for center-block
</div>
</div>
<div class = "row">
<div class = "center-block" style = "width:200px; background-color:#ccc;">
This is an example for center-block
</div>
</div>