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