the big box should be as high as possible below the
  small box).</p>
  <div>
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   <span class="a">A</span>
   <p class="a">AAAA</p>
   <span class="b">B</span>
   <p class="b">BBBB</p>
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   dummy text dummy text dummy text dummy text dummy text dummy text
   dummy text dummy text dummy text dummy text dummy text dummy text
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   du