{TAIL ~ Each} of the mating surfaces 121 has a portion formed with {HEAD ~ a positioning hole} 13 
{ TAIL ~ Each } of the mating surfaces 121 has a portion formed with { HEAD ~ a positioning hole } 13
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH