( ( Brass ( ( An alloy ) ( of ( ( zinc and ) copper ) ) ) ) . )
(ROOT (NP (NP (NNS Brass)) (NP (NP (DT An) (NN alloy)) (PP (IN of) (NP (NN zinc) (CC and) (NN copper)))) (. .)))
Brass An alloy of zinc and copper .
(ROOT (S (NP (NNP Brass) (NNP alloy)) (VP (VBZ is) (VP (VBN made) (PP (IN from) (NP (NN copper) (CC and) (NN zinc))))) (. .)))