How can I insert vertical blank space into an HTML document?

Read up some on CSS. It’s fun: CSS: em, px, pt, cm, in…

<style>
  .bottom-three {
     margin-bottom: 3cm;
  }
</style>


<p class="bottom-three">
   This is the first question?
</p>
<p class="bottom-three">
   This is the second question?
</p>