title: Cannot create an instance of the abstract class or interface
body: <p>I'm not familiar on using <code>abstract class</code>.</p>
  
  <p>I'm trying to call a <code>abstract class</code> and get this error <code>Cannot create an instance of the abstract class or interface</code> and I already research this error but I'm really confused on this.</p>
  
  <p>Here's my code:</p>
  
  <pre><code>        string B1String;
          while ((B1String = OasisFile.ReadLine()) != null)
          {
            Questions_Base oQuestions_Base = new Questions_Base(); // error here
            oQuestions_Base.Import(B1String);
          }
  </code></pre>
  
  <p>Please advice me.. thanks!</p>