( ( The ( cell wall ) ) ( ( surrounds ( the ( cell membrane ) ) ) . ) )
(ROOT (S (NP (DT The) (NN cell) (NN wall)) (VP (VBZ surrounds) (NP (DT the) (NN cell) (NN membrane))) (. .)))
The cell wall surrounds the cell membrane .
(ROOT (S (NP (JJ Biological) (NNS membranes)) (VP (VP (VBP surround) (NP (NNS cells))) (CC and) (VP (VBP serve) (S (VP (TO to) (VP (VB keep) (NP (NP (DT the) (NNS insides)) (VP (VBN separated) (PP (IN from) (NP (DT the) (NNS outsides)))))))))) (. .)))