( ( The connection ) ( ( is ( ( a substance ) ( that ( ( ( is ( a ( good conductor ) ) ) , ) ( for ( ( example , ) ( a ( copper wire ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN connection)) (VP (VBZ is) (NP (NP (DT a) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (NP (DT a) (JJ good) (NN conductor)) (, ,) (PP (IN for) (NP (NP (NN example)) (, ,) (NP (DT a) (NN copper) (NN wire))))))))) (. .)))
The connection is a substance that is a good conductor, for example, a copper wire.
(ROOT (S (NP (NN Copper)) (VP (VBZ conducts) (NP (NP (NN electricity)) (NP (DT the) (JJS best)))) (. .)))