Among the eight regions, {HEAD ~ four regions} are provided in {TAIL ~ the outer peripheral portion} and four regions are provided in the inner peripheral portion 
are provided in
Among the eight regions , { HEAD ~ four regions } are provided in { TAIL ~ the outer peripheral portion } and four regions are provided in the inner peripheral portion
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH