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