<html><head><script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js"></script><script>$(document).ready(function(){ $("p").filter(document.getElementById("intro")).css("background-color","yellow");});</script></head><body><h1>Welcome to My Homepage</h1><p>My name is Donald.</p><p id="intro">I live in Duckburg.</p><p>My best friend is Mickey.</p></body></html>