<h1>Squares</h1>
 <ul class="list_one">
   <li>Forest</li>
   <li>Ocean</li>
   <li>Desert</li>
   <li>Tundra</li>
</ul>

<h1>Circles</h1>
<ul class="list_two">
   <li>Cats</li>
   <li>Dogs</li>
   <li>Fish</li>
   <li>Birds</li>
 </ul>

<h1>Upper Roman Numerals</h1>
<ul class="list_three">
  <li>January</li>
  <li>February</li>
  <li>March</li>
  <li>April</li>
</ul>

<h1>Upper Alpha (Letters)</h1>
<ul class="list_four">
  <li>Spring</li>
  <li>Summer</li>
  <li>Autumn</li>
  <li>Winter</li>
</ul>

.list_one {
  list-style-type: square;
}

.list_two {
  list-style-type: circle;
}

.list_three {
  list-style-type: upper-roman;
}

.list_four {
  list-style-type: upper-alpha;
}