{TAIL ~ A propped block} 31 is joined to {HEAD ~ a lower side} of the connecting block 3 
{ TAIL ~ A propped block } 31 is joined to { HEAD ~ a lower side } of the connecting block 3
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH