There is apparatus for creating a beam of a material being input thereto and for selectively including or not including respective ones of {HEAD ~ a plurality} of {TAIL ~ materials} within the beam 
of
There is apparatus for creating a beam of a material being input thereto and for selectively including or not including respective ones of { HEAD ~ a plurality } of { TAIL ~ materials } within the beam
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH