{HEAD ~ The Solvay process} uses {TAIL ~ poisonous ammonia gas} with a complex column system to extract the said products 
uses
{ HEAD ~ The Solvay process } uses { TAIL ~ poisonous ammonia gas } with a complex column system to extract the said products
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH