Quick CSS question – hiding Blah Tag

Hi all,

I’m hoping for some CSS help! I can’t seem to figure this out.

<div id="One">
<ul id="two">
<li id="three">Blah Blah</li>
<li id="four">Blah Blah</li>
</ul>
</div>

How do i hide “four” via CSS?

i have tried:

#four { display:none; }

But that doesn’t work.

Thanks for any help!