( ( The sternum ) ( ( is ( ( ( ( ( an elongated ) , ) ( flattened bone ) ) , ) ( forming ( ( the ( middle portion ) ) ( of ( ( the ( anterior wall ) ) ( of ( the thorax ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN sternum)) (VP (VBZ is) (NP (NP (DT an) (NN elongated)) (, ,) (VP (VBN flattened) (NP (NN bone))) (, ,) (VP (VBG forming) (NP (NP (DT the) (JJ middle) (NN portion)) (PP (IN of) (NP (NP (DT the) (NN anterior) (NN wall)) (PP (IN of) (NP (DT the) (NN thorax))))))))) (. .)))
The sternum is an elongated, flattened bone, forming the middle portion of the anterior wall of the thorax.
(ROOT (S (NP (DT The) (NN sternum)) (VP (VBZ is) (NP (NP (DT the) (NN name)) (PP (IN of) (NP (NP (DT the) (JJ elongated) (NN bony) (NN structure)) (SBAR (WHNP (WDT that)) (S (VP (VBZ anchors) (NP (DT the) (JJ anterior) (JJ thoracic) (NN cage))))))))) (. .)))