Select all the description tags from this HTML code.
Input: <html>
    <head>
        <title>Sample Site</title>
        <meta name="description" content="Sample site for testing purposes">
        <meta name="keywords" content="testing, sample">
    </head>
meta name="description" content="Sample site for testing purposes"
meta name="keywords" content="testing, sample"
<title>Sample Site</title>
<meta name="description" content="Sample site for testing purposes">
<meta name="keywords" content="testing, sample">
<meta name="description" content="Sample site for testing purposes">
<meta name="keywords" content="testing, sample">