( ( This step ) ( ( consists ( of ( two layers ) ) ) . ) )
(ROOT (S (NP (DT This) (NN step)) (VP (VBZ consists) (PP (IN of) (NP (CD two) (NNS layers)))) (. .)))
This step 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)))) (. .)))