下拉用户输入，然后列出并允许在HTML页面上进行编辑

<select>
  <option value="option1">选项1</option>
  <option value="option2">选项2</option>
  <option value="option3">选项3</option>
</select>

<select>
  <option value="option1">选项1</option>
  <option value="option2">选项2</option>
  <option value="option3">选项3</option>
  <option value="custom">自定义选项</option>
</select>
<input type="text" id="customOption" style="display: none;">

<script>
  const selectElement = document.querySelector('select');
  const customOptionInput = document.getElementById('customOption');

  selectElement.addEventListener('change', function() {
    if (selectElement.value === 'custom') {
      customOptionInput.style.display = 'block';
    } else {
      customOptionInput.style.display = 'none';
    }
  });
</script>