title: How can i remove same item in list
body: <p>Could you help me? I cant remove the same item in a list.</p>
  
  <pre class="lang-cs prettyprint-override"><code>List&lt;string&gt; text = new List&lt;string&gt;();
  text.Add("A");
  text.Add("B");
  text.Add("C");
  text.Add("D");
  text.Add("D");
  text.Add("A");
  foreach(string i in text)
  {
   Console.WriteLine(i);
  }
  </code></pre>
  
  <p>the result is A,B,C,D,D,A  but I need to be B,C . How can i do?</p>