title: Selecting <li> in groups of 3
body: <p>I am trying to select <code>&lt;li&gt;</code> in groups of 3, currently I am using <code>:gt</code> and <code>:lt</code> like this</p>
  
  <pre><code> $('.events_list li:lt(7):gt(3)').css('display', 'block');
  </code></pre>
  
  <p>This is ok but seems like there may be a better way. I just want to click a button and select the next 3 <code>&lt;li&gt;</code>.</p>