title: How to highlight a text while reading (SpeechSynthesizer) a specific word in Textbox/RichtextBox?
body: <p>SpeechSynthesizer reader = new SpeechSynthesizer();</p>
  
  <p>reader.SpeakAsync(richTextBox1.SelectedText);</p>
  
  <p>// highlight a text while reading (SpeechSynthesizer) a specific word in richTextBox1.</p>