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<html><head><script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script><script>$(document).ready(function(){ $("div:not(:has(h1))").css("background-color", "yellow");});</script></head><body><div> <h1>This is a heading (h1)</h1> <p>This is a paragraph.</p></div><div> <h2>This is a heading (h2)</h2> <p>This is a paragraph.</p></div><div> <h3>This is a heading (h3)</h3> <p>This is a paragraph.</p></div></body></html>