As a result, {HEAD ~ the average position} of {TAIL ~ the stage} can be measured more accurately than any of its individual positions 
As a result , { HEAD ~ the average position } of { TAIL ~ the stage } can be measured more accurately than any of its individual positions
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH