{TAIL ~ An important role} for obtaining this result is played by {HEAD ~ the arcuate shape} 16 of the bottom 9 of trough 8 
{ TAIL ~ An important role } for obtaining this result is played by { HEAD ~ the arcuate shape } 16 of the bottom 9 of trough 8
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH