index.html
<html>
<head>
<link id="news" rel="import" href="/news.html" />
</head>
<body>
<div id="news-placeholder"></div>
<script>
var content = document.getElementById('news').import;
var items = content.getElementsByClassName('news-item')
items.length && document.getElementById('news-placeholder').appendChild(items[0])
</script>
</body>
</html>
news.html
<div class="news">
<div class="news-item">news 1</div>
<div class="news-item">news 2</div>
<div class="news-item">news 3</div>
</div>