{HEAD ~ The process} 5 wherein unreacted olefin is removed from {TAIL ~ the titanium halide} before the electron donor is added 
{ HEAD ~ The process } 5 wherein unreacted olefin is removed from { TAIL ~ the titanium halide } before the electron donor is added
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH