( ( The bronzes ) ( ( are ( alloys ( of ( ( copper and ) tin ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS bronzes)) (VP (VBP are) (NP (NP (NNS alloys)) (PP (IN of) (NP (NN copper) (CC and) (NN tin))))) (. .)))
The bronzes are alloys of copper and tin.
(ROOT (S (NP (NN Bronze)) (VP (VBZ is) (NP (NP (DT an) (NN alloy)) (PP (IN of) (NP (NN copper) (CC and) (NN tin))))) (. .)))