{HEAD ~ The number} of {TAIL ~ metallic probes} can be controlled to thereby control the amount of metallic ions produced 
of
{ HEAD ~ The number } of { TAIL ~ metallic probes } can be controlled to thereby control the amount of metallic ions produced
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH