title: How to use tail-recursive to implement a recursive function
body: <blockquote>
    <p>(replicate-to-length '(a b c) 8)</p>
  </blockquote>
  
  <p>(a b c a b c a b)</p>
  
  <blockquote>
    <p>(replicate-to-length '(a b c) 2)</p>
  </blockquote>
  
  <p>(a b)</p>