title: Select hides under the table in Bootstrap 4
body: <p>I am beginner web developer. I use in my project Bootstrap 4.</p>
  <p>Here is my preview: <a href="http://serwer1356363.home.pl/_nauka/" rel="nofollow noreferrer">http://serwer1356363.home.pl/_nauka/</a> - after click &quot;Liczba sztuk&quot; - select I have problem.</p>
  <p>Items from select are hidden under the table (you can't see everything).</p>
  <p>Sorry for not pasting my code here, but from within the code you would not see the problem.</p>
  <p>How can I repair it?</p>
  <p>Please help.</p>