{HEAD ~ Substantial improvements} in the control of pollutants from internal combustion engines may be obtained by pre drying a catalyst/hydrocarbon trap system and preferably incorporating a water trap in {TAIL ~ a catalyst/hydrocarbon trap system} 
{ HEAD ~ Substantial improvements } in the control of pollutants from internal combustion engines may be obtained by pre drying a catalyst / hydrocarbon trap system and preferably incorporating a water trap in { TAIL ~ a catalyst / hydrocarbon trap system }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL