<script type="text/javascript" src="/js/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("button").click(function(){
$("p").append(" <b>Hello world!</b>");
<p>This is a paragraph.</p>
<p>This is another paragraph.</p>
<button>在每个 p 元素的结尾添加内容</button>