Replace decagram example with centiliter

src/website/article/metric-poetry/index.html

@@ -52,14 +52,18 @@ <h2>Notes</h2>
                Since a "mil" can be either a millimeter or a milliliter, the meaning needs to be
                determined from context.&nbsp;
                A better word for millimeter would be "mim", but that ship has already sailed.&nbsp;
-               No one is ever going to say that a GLOCK 19 (G19 9&times;19mm) is a
+               No one is ever going to say that a GLOCK 19 (G19&nbsp;9&times;19mm) is a
                9&nbsp;mim.&nbsp;
             </li>
             <li>
-               Never use the lesser known in-between unit terms, like hectometer, centiliter, or
-               decagram, as they are useless.&nbsp;
-               There's no reason to be poetic about it &mdash; only a moron would say "3 decagrams"
-               instead of "30 grams".&nbsp;
+               It's best to never use the lesser known in-between unit terms, like
+               hectometer, centiliter, or decagram, for the same reason you don't use archaic
+               words that fell out of use a century ago.&nbsp;
+               For example, it would be unnatural to say "3&nbsp;centiliters" instead of
+               "30&nbsp;cc" or "30&nbsp;ml".&nbsp;
+               Note that some unit terms that are generally obscure may in fact be commonly used in
+               specific geographic regions, such as Germans saying "deka" to mean
+               10&nbsp;g.&nbsp;
             </li>
             <li>
                Avoid the Latin gibberish of the extreme prefixes except in scientific