title: Why odt file can not be opened by zip but can be opened by open office?
body: <p>I think odt files are ziped files.</p>
  
  <p>Why odt file can not be opened by zip but can be opened by open office?</p>
  
  <p>And a zip file not complete can also be unziped??</p>
  
  <p>Who is familiar with zip format?</p>