( ( The lungs ) ( ( are ( surrounded ( by ( ( a ( protective lining ) ) ( which ( consists ( of ( ( two membranes ) ( called ( the pleura ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS lungs)) (VP (VBP are) (VP (VBN surrounded) (PP (IN by) (NP (NP (DT a) (JJ protective) (NN lining)) (SBAR (WHNP (WDT which)) (S (VP (VBZ consists) (PP (IN of) (NP (NP (CD two) (NNS membranes)) (VP (VBN called) (NP (DT the) (NN pleura)))))))))))) (. .)))
The lungs are surrounded by a protective lining which consists of two membranes called the pleura.
(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)))) (. .)))