Set the bottom margins of all img elements to 10px.

<html>
<head>
<style>img {
border: solid 2px darkCyan;
margin-bottom: 10px;
padding: 5px;
height: 130px;
width: 130px;
}</style>
</head>
<body>
<img src="https://mimo.app/r/shuttle.png">
<img src="https://mimo.app/r/moon.png">
<br>
<img src="https://mimo.app/r/moon2.png">
<img src="https://mimo.app/r/moonlanding.png">

<script src="script.js"></script>
</body>
</html>]]>

Make sure to type margin-bottom: 10px;.