( ( ( This mixture ) ( of ( ( copper and ) zinc ) ) ) ( ( forms ( ( the alloy ) ( commonly ( known ( as brass ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT This) (NN mixture)) (PP (IN of) (NP (NN copper) (CC and) (NN zinc)))) (VP (VBZ forms) (NP (NP (DT the) (NN alloy)) (VP (ADVP (RB commonly)) (VBN known) (PP (IN as) (NP (NN brass)))))) (. .)))
This mixture of copper and zinc forms the alloy commonly known as brass .
(ROOT (S (NP (NNP Brass) (NNP alloy)) (VP (VBZ is) (VP (VBN made) (PP (IN from) (NP (NN copper) (CC and) (NN zinc))))) (. .)))