The second driver circuit drives {HEAD ~ a second load element} formed of {TAIL ~ the second material} based on the second bias voltage 
formed of
The second driver circuit drives { HEAD ~ a second load element } formed of { TAIL ~ the second material } based on the second bias voltage
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH