( ( ( The area ) ( ( in which ) ( ( all ( of ( ( Earth 's ) water ) ) ) exists ) ) ) ( ( is ( called ( the hydrosphere ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN area)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (NP (DT all)) (PP (IN of) (NP (NP (NNP Earth) (POS 's)) (NN water)))) (VP (VBZ exists))))) (VP (VBZ is) (VP (VBN called) (NP (DT the) (NN hydrosphere)))) (. .)))
The area in which all of Earth's water exists is called the hydrosphere .
(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))))))))) (. .)))