{HEAD ~ The centrifuge} includes {TAIL ~ a receiving chamber} with a selectively formed annular slot therein 
includes
{ HEAD ~ The centrifuge } includes { TAIL ~ a receiving chamber } with a selectively formed annular slot therein
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH