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<script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js">
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$(document).ready(function(){
$("p").filter(":even").css("background-color","yellow");
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<body>
<p>My name is Donald (index 0).</p>
<p>I live in Duckburg (index 1).</p>
<p>My best friend is Mickey (index 2).</p>
<p>My name is Daisy (index 3).</p>
<p>I live in Duckburg (index 4).</p>
<p>My best friend is Minnie (index 5).</p>
</body>
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