<Circles xmlns="http://schemas.openxmlformats.org/Circles/v1" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:extA="http://schemas.openxmlformats.org/Circles/extension" xmlns:extB="http://schemas.openxmlformats.org/Circles/extension">
  <extB:Blink>
   <Circle Center="0,0" Radius="20" Color="Blue"/>
   <Circle Center="25,0" Radius="20" Color="Black"/>
   <Circle Center="50,0" Radius="20" Color="Red"/>
  </extB:Blink>
</Circles>