index.html

<!DOCTYPE html>

<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title></title>
    <meta name="description" content="">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="style.css">
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css"
        integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
</head>

<body>
    <div class="text-center">
        <button class="cr">Car</button>
        <button class="bie">aeroplane</button>
        <button class="pn">bike</button>
        <button class="ce">cycle</button>
    </div>
    <div class="text-center">
        <img class="img-responsive cars" src="car.jpg" alt="">
        <img class="img-responsive bike bikes" src="bike.jpg" alt="">
        <img class="img-responsive plane planes" src="plane.jpg" alt="">
        <img class="img-responsive cycle cycles" src="cycle.jpg" alt="">
    </div>



    <script src="https://code.jquery.com/jquery-3.5.1.min.js"
        integrity="sha256-9/aliU8dGd2tb6OSsuzixeV4y/faTqgFtohetphbbj0=" crossorigin="anonymous"></script>
    <script src="script.js"></script>
</body>

</html>