<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<div class="container">
<div class="row">
<div class="col-sm-3">
<div class="card">
<img class="card-img-top" src="https://placeholdit.imgix.net/~text?txtsize=33&txt=250×100-1&w=250&h=100" alt="Card image cap">
<div class="card-block">
<h4 class="card-title">Card title</h4>
<p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's content.</p>
<a href="#" class="btn btn-primary">Sploink!</a>
</div>
</div>
</div>
<div class="col-sm-3">
<div class="card">
<img class="img-fluid" src="https://placeholdit.imgix.net/~text?txtsize=33&txt=250×100-2&w=250&h=100" alt="Card image cap">
<div class="card-block">
<h4 class="card-title">Card title</h4>
<p class="card-text">Some quick example text to build on the card title and make up the bulk of the card's content.</p>
<a href="#" class="btn btn-primary">Boink!</a>
</div>
</div>
</div>