( ( Rivers ( of ( lava Earth ) ) ) ( ( has ( ( ( ( ( ( a ( thin layer ) ) ( of crust ) ) , ) ( ( ( ( a ( thick mantle ) ) , ) ( a ( molten ( outer core ) ) ) ) ( -LRB- ( ( which ( produces ( its ( magnetic field ) ) ) ) -RRB- ) ) ) ) and ) ( a ( solid ( inner core ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Rivers)) (PP (IN of) (NP (NNP lava) (NNP Earth)))) (VP (VBZ has) (NP (NP (NP (DT a) (JJ thin) (NN layer)) (PP (IN of) (NP (NN crust)))) (, ,) (NP (NP (DT a) (JJ thick) (NN mantle)) (, ,) (NP (DT a) (JJ molten) (JJ outer) (NN core)) (PRN (-LRB- -LRB-) (SBAR (WHNP (WDT which)) (S (VP (VBZ produces) (NP (PRP$ its) (JJ magnetic) (NN field))))) (-RRB- -RRB-))) (CC and) (NP (DT a) (JJ solid) (JJ inner) (NN core)))) (. .)))
Rivers of lava Earth has a thin layer of crust, a thick mantle, a molten outer core ( which produces its magnetic field ) and a solid inner core.
(ROOT (S (NP (NP (DT The) (JJ outer) (NN core)) (PP (IN of) (NP (DT the) (NN earth)))) (VP (VBZ is) (ADJP (JJ molten))) (. .)))