( There ( ( are ( rocks ( that ( compose ( ( the crust ) ( of ( the planet ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (NNS rocks)) (SBAR (WHNP (WDT that)) (S (VP (VBP compose) (NP (NP (DT the) (NN crust)) (PP (IN of) (NP (DT the) (NN planet))))))))) (. .)))
There are rocks that compose the crust of the planet.
(ROOT (S (NP (NP (DT The) (NN earth) (POS 's)) (NN crust)) (VP (VBZ is) (VP (VBN composed) (PP (IN of) (NP (JJ igneuos) (NN rock))))) (. .)))