( It ( ( is ( composed ( of ( ( two layers ) ( of ( ( cells : ) ( ( One layer ) ( immediately ( surrounds ( the organ ) ) ) ) ) ) ) ) ) ) ; ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (VP (VBN composed) (PP (IN of) (NP (NP (CD two) (NNS layers)) (PP (IN of) (NP (NP (NNS cells)) (: :) (NP (NP (CD One) (NN layer)) (VP (ADVP (RB immediately)) (VBZ surrounds) (NP (DT the) (NN organ)))))))))) (: ;)))
It is composed of two layers of cells: One layer immediately surrounds the organ;
(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)))) (. .)))