{TAIL ~ The sidewalls} 57 typically define {HEAD ~ an obtuse angle} with the bottom surface 55 of the recess 53 
{ TAIL ~ The sidewalls } 57 typically define { HEAD ~ an obtuse angle } with the bottom surface 55 of the recess 53
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH