title: How can I make an HTML table with subcolumns?
body: <p>I would like to make an HTML table that expresses the following structure:</p>
  
  <pre><code>ColumnHeading1            ColumnHeading2
  SubHeading1A SubHeading1B SubHeading2A Subheading2B
  data1A       data1B       data2A       data2B
  data1A       data1B       data2A       data2B
  data1A       data1B       data2A       data2B
  data1A       data1B       data2A       data2B
  ...
  </code></pre>
  
  <p>How can I do this with tags like <code>&lt;table&gt;</code>,<code>&lt;tr&gt;</code>,<code>&lt;th&gt;</code>,<code>&lt;td&gt;</code>? I don't know how to align ColumnHeading2 with SubHeading2A.</p>