{TAIL ~ The Ra} and {HEAD ~ Ra} may preferably provide Ra/Ra ratio of at most 0.8 
{ TAIL ~ The Ra } and { HEAD ~ Ra } may preferably provide Ra / Ra ratio of at most 0.8
TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH