Solution de l'exercice 1

`exercice1.php`

<?php
  $url = "https://prog101.com/cours/kb9/anneaux.html";
  @ $contenu = file_get_contents($url);

  if ($contenu === false) {
    $contenu = "Impossible d'ouvrir $url";
  } else {
    $contenu = strip_tags($contenu, "<strong>");
  }
?>
<!DOCTYPE html>
<html lang="fr">
<head>
  <meta charset="UTF-8">
  <title>Exercice 1</title>
</head>
<body>
  <p><?= $contenu ?></p>
</body>
</html>