( Copper ( ( ( conducts electricity ) ( better ( than ( aluminum does ) ) ) ) . ) )
(ROOT (S (NP (NN Copper)) (VP (VBZ conducts) (NP (NN electricity)) (ADVP (ADVP (RBR better)) (SBAR (IN than) (S (NP (NN aluminum)) (VP (VBZ does)))))) (. .)))
Copper conducts electricity better than aluminum does.
(ROOT (S (NP (NN Copper)) (VP (VBZ conducts) (NP (NP (NN electricity)) (NP (DT the) (JJS best)))) (. .)))