{HEAD ~ The propped block} has {TAIL ~ several spaced horizontal propped surfaces} on the bottom thereof which are formed at different heights with slopes formed in between 
{ HEAD ~ The propped block } has { TAIL ~ several spaced horizontal propped surfaces } on the bottom thereof which are formed at different heights with slopes formed in between
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH