MULTISELECT DROPDOWN
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<!DOCTYPE html>
<html lang="en">
<head>
  <title>Bootstrap </title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.1/dist/css/bootstrap.min.css" rel="stylesheet"> 
  <script src="https://cdn.jsdelivr.net/npm/@popperjs/core@2.9.2/dist/umd/popper.min.js" integrity="sha384-IQsoLXl5PILFhosVNubq5LC7Qb9DXgDA9i+tQ8Zj3iwWAwPtgFTxbJ8NT4GN1R8p" crossorigin="anonymous"></script>
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<body>
    <h2> Multiselect dropdown </h2>
	<select class="form-select" size="3" aria-label="size 3 select example" multiple>
	  <option selected>Open this select menu</option>
	  <option value="1">One</option>
	  <option value="2">Two</option>
	  <option value="3">Three</option>
	</select>
</body>
</html>