{HEAD ~ The catalyst component} comprises a magnesium chloride support, a titanium trichloride, {TAIL ~ an aluminum trichloride} and an organic phosphite 
comprises
{ HEAD ~ The catalyst component } comprises a magnesium chloride support , a titanium trichloride , { TAIL ~ an aluminum trichloride } and an organic phosphite
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH