{HEAD ~ Tall structures} can comprise electronic components, LEDs, {TAIL ~ OLEDS}, or OLETs 
comprise
{ HEAD ~ Tall structures } can comprise electronic components , LEDs , { TAIL ~ OLEDS } , or OLETs
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH