Bootstrap中用于嵌入式内容（长宽比为16：9）的容器
使用Bootstrap中的.embed-response类为嵌入式内容设置容器。
对于嵌入内容的16：9宽高比，请使用 embed-sensitive-16by9类
示例
<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Example</title>
<link href = "/bootstrap/css/bootstrap.min.css" rel = "stylesheet">
<script src = "/scripts/jquery.min.js"></script>
<script src = "/bootstrap/js/bootstrap.min.js"></script>
</head>
<body>
<div class = "container">
<h2>Eclipse Refactoring</h2>
<p>To refactor code in Eclipse, try the below given steps in the video:</p>
<div class = "embed-responsive embed-responsive-16by9">
<iframe class = "embed-responsive-item" src = "https://www.youtube.com/embed/YFVV6RAUnNg "></iframe>
</div>
</div>
</body>
</html>