index.html

<!DOCTYPE html>
<html lang="ja">

<head>
    <meta charset="utf-8" />
    <title>Javascript Practice</title>
    <link rel="stylesheet" href="css/style.css" />
</head>

<body>
    <h1>画像クイズ</h1>
    <input id="set_quiz" type="button" value="出題" />
    <h2 id="question"></h2>
    <div class="items">
        <div class="item">
            <p>1.</p>
            <img id="img1" />
        </div>
        <div class="item">
            <p>2.</p>
            <img id="img2" />
        </div>
        <div class="item">
            <p>3.</p>
            <img id="img3" />
        </div>
        <div class="item">
            <p>4.</p>
            <img id="img4" />
        </div>
        <div class="item">
            <p>5.</p>
            <img id="img5" />
        </div>
        <div class="item">
            <p>6.</p>
            <img id="img6" />
        </div>
    </div>
</body>

</html>
<script src="js/index.js"></script>