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