title: Split string on several words, and track which word split it where
body: <p>I am trying to split a long string based on an array of words.  For Example:</p>
  
  <p>Words: trying, long, array</p>
  
  <p>Sentence: "I am trying to split a long string based on an array of words."</p>
  
  <p>Resulting string array:</p>
  
  <ul>
  <li>I am</li>
  <li><em>trying</em></li>
  <li>to split a</li>
  <li><em>long</em></li>
  <li>string based on an</li>
  <li><em>array</em></li>
  <li>of words</li>
  </ul>
  
  <p>Multiple instances of the same word is likely, so having two instances of trying cause a split, or of array, will probably happen.</p>
  
  <p>Is there an easy way to do this in .NET?</p>