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