( ( The ( hierarchical structure ) ) ( ( consists ( of ( two layers ) ) ) . ) )
(ROOT (S (NP (DT The) (JJ hierarchical) (NN structure)) (VP (VBZ consists) (PP (IN of) (NP (CD two) (NNS layers)))) (. .)))
The hierarchical structure consists of two layers.
(ROOT (S (NP (NP (DT The) (NN pleura)) (SBAR (WHNP (WDT that)) (S (VP (VBZ surrounds) (NP (DT the) (NNS lungs)))))) (VP (VBZ consists) (PP (IN of) (NP (CD two) (NNS layers)))) (. .)))