( ( ( The ( outer part ) ) ( of ( the core ) ) ) ( ( is ( liquid metal ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ outer) (NN part)) (PP (IN of) (NP (DT the) (NN core)))) (VP (VBZ is) (ADJP (JJ liquid) (NN metal))) (. .)))
The outer part of the core is liquid metal.
(ROOT (S (NP (DT The) (JJ outer) (NN core)) (VP (VBZ is) (VP (VBN made) (PP (IN of) (NP (JJ liquid) (NN metal))))) (. .)))