( ( The cells ) ( ( consist ( of ( ( two layers ) ( of material ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS cells)) (VP (VBP consist) (PP (IN of) (NP (NP (CD two) (NNS layers)) (PP (IN of) (NP (NN material)))))) (. .)))
The cells consist of two layers of material.
(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)))) (. .)))