网址：http://www.w3cschool.cc/bootstrap/bootstrap-responsive-utilities.html
<div class="container" style="padding: 40px;">
<div class="row visible-on">
<div class="col-xs-6 col-sm-3" style="
box-shadow: inset 1px -1px 1px #444, inset -1px 1px 1px #444;">
<span class="hidden-xs">特别小型</span>
<span class="visible-xs">✔ 在特别小型设备上可见</span>
</div>
<div class="col-xs-6 col-sm-3" style="
box-shadow: inset 1px -1px 1px #444, inset -1px 1px 1px #444;">
<span class="hidden-sm">小型</span>
<span class="visible-sm">✔ 在小型设备上可见</span>
</div>
<div class="clearfix visible-xs"></div>
<div class="col-xs-6 col-sm-3" style="
box-shadow: inset 1px -1px 1px #444, inset -1px 1px 1px #444;">
<span class="hidden-md">中型</span>
<span class="visible-md">✔ 在中型设备上可见</span>
</div>
<div class="col-xs-6 col-sm-3" style="
box-shadow: inset 1px -1px 1px #444, inset -1px 1px 1px #444;">
<span class="hidden-lg">大型</span>
<span class="visible-lg">✔ 在大型设备上可见</span>
</div>
</div>
</div>