title: regex for matching literal string combinations
body: <p>I'm a noob with regex.</p>
  
  <p>I have to match literally different combinations of strings. Like in the example:</p>
  
  <pre><code>"feed the cat."
  "feed the dog."
  "feed the bear."
  </code></pre>
  
  <p>but NOT</p>
  
  <pre><code>"feed the eagle."
  "feed the monkey."
  "feed the donkey."
  </code></pre>
  
  <p>I tried something like <code>/^feed the [cat|dog|bear].$/</code> but it doesn't work. The cheatsheet available on the net explain a lot of complicated things, but not how I can match several strings literally...</p>
  
  <p>Thank you for the help.</p>