{HEAD ~ The rolling elements} may comprise ball bearings, spherical elements, cylindrical bearings, tapered roller bearings, or {TAIL ~ any other suitable friction reducing element} 
comprise
{ HEAD ~ The rolling elements } may comprise ball bearings , spherical elements , cylindrical bearings , tapered roller bearings , or { TAIL ~ any other suitable friction reducing element }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL