tion for the illustration of reference
vs. device pixel">[D]</A></SPAN></p>
</div>


<div class="example"><P style="display:none">示例：</P>
<pre><code class="css">
h1 { margin: 0.5in }      /* inches  */
h2 { line-height: 3cm }   /* centimeters */
h3 { word-spacing: 4mm }  /* millimeters */
h4 { font-size: 12pt }    /* points */
h4 { font-size: 1pc }     /* picas */
p  { font-size: 12px }    /* px */
</code></pre>
</div>

<h3>4.3.3  <a name="percentage-units">百分比</a></h3>

<p>百分比值（本规