{HEAD ~ The invention} requires three chemicals CO2, Ca2, and {TAIL ~ sodium chloride NaCl} to produce NaHCO3 
requires
{ HEAD ~ The invention } requires three chemicals CO2 , Ca2 , and { TAIL ~ sodium chloride NaCl } to produce NaHCO3
HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH