<!DOCTYPE html>
<html>
    <head>
        <title>My web page</title>
    </head>
    <body>
        <h1>Hello, world!</h1>
        <p>This is my first web page.</p>
        <p>It contains a 
             <strong>main heading</strong> and <em> paragraph </em>.
        </p>
    </body>
</html>