( ( ( The ( entire surface ) ) ( of ( the alveolus ) ) ) ( ( ( is normally ) ( covered ( by ( epithelial cells ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ entire) (NN surface)) (PP (IN of) (NP (DT the) (NNS alveolus)))) (VP (VBZ is) (ADVP (RB normally)) (VP (VBN covered) (PP (IN by) (NP (JJ epithelial) (NNS cells))))) (. .)))
The entire surface of the alveolus is normally covered by epithelial cells.
(ROOT (S (NP (NNP Epithelial) (. ?) (NNP tissue)) (VP (VBZ consists) (PP (IN of) (NP (NP (NNS cells)) (SBAR (WHNP (WHNP (WDT that) (NN cover)) (NP (JJ inner) (CC and) (JJ outer) (NN body))) (S (VP (VBZ surfaces))))))) (. .)))