( Hydropower ( ( ( is still ) ( ( ( ( the ( ( most significant ) source ) ) ( of ( renewable energy ) ) ) , ) ( producing ( ( ( ( 20 percent ) ( of ( ( the ( world 's ) ) electricity ) ) ) and ) ( ( 10 percent ) ( of ( that ( of ( the ( United States ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Hydropower)) (VP (VBZ is) (ADVP (RB still)) (NP (NP (DT the) (ADJP (RBS most) (JJ significant)) (NN source)) (PP (IN of) (NP (JJ renewable) (NN energy))) (, ,) (VP (VBG producing) (NP (NP (NP (CD 20) (NN percent)) (PP (IN of) (NP (NP (DT the) (NN world) (POS 's)) (NN electricity)))) (CC and) (NP (NP (CD 10) (NN percent)) (PP (IN of) (NP (NP (DT that)) (PP (IN of) (NP (DT the) (NNP United) (NNPS States)))))))))) (. .)))
Hydropower is still the most significant source of renewable energy, producing 20 percent of the world's electricity and 10 percent of that of the United States.
(ROOT (S (NP (NNP Hydropower)) (VP (VBZ is) (NP (NP (DT the) (ADJP (RBS most) (RB widely) (VBN used)) (NN form)) (PP (IN of) (NP (NP (JJ renewable) (NN energy)) (PP (IN in) (NP (DT the) (NN world))))))) (. .)))