( ( The hydrosphere ) ( ( is ( ( the ( `` ( water ( layer '' ) ) ) ) ( of ( the Earth ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN hydrosphere)) (VP (VBZ is) (NP (NP (DT the) (`` ``) (NN water) (NN layer) ('' '')) (PP (IN of) (NP (DT the) (NN Earth))))) (. .)))
The hydrosphere is the "water layer" of the Earth.
(ROOT (S (NP (NP (DT The) (NN surface)) (PP (IN of) (NP (NN earth)))) (VP (VBZ is) (VP (VBN covered) (PP (IN by) (NP (NP (DT a) (ADJP (RB relatively) (JJ thin)) (NN layer)) (PP (IN of) (NP (NP (NN water)) (VP (VBN called) (NP (DT the) (NN hydrosphere))))))))) (. .)))