{TAIL ~ This mixture} is then contacted with the remainder of {HEAD ~ the electron donor or transition metal component} for a second contact time of less and 110 seconds 
{ TAIL ~ This mixture } is then contacted with the remainder of { HEAD ~ the electron donor or transition metal component } for a second contact time of less and 110 seconds
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH