查看可用的字体图标列表：
http://www.runoob.com/try/demo_source/bootstrap3-glyph-icons.htm
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>图标应用</title>
<!-- Bootstrap -->
<link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">
</head>
<body>
<!-- 调用 -->
<span class="glyphicon glyphicon-adjust"></span>
</body>
</html>