title: How can remove the <scheduled date> in the org agenda view quickly?
body: <p>In the emacs org agenda view(today), I schedule some tasks with the <code>&lt;scheduled date&gt;</code>. But now I want to remove the <code>&lt;scheduled date&gt;</code> single task or mutli tasks together. (Don't want to schedule them to the other day).</p>
  
  <p>Now I have to <code>&lt;TAB&gt;</code> each tasks, and delete the <code>&lt;scheduled date&gt;</code> line.</p>
  
  <p>Is there any quick key (speed key?) to do it?</p>