( ( As ( ( America 's ) ( ( most abundant ) ( energy source ) ) ) ) ( , ( coal ( ( ( is currently ) ( used ( to ( generate ( ( ( nearly 60 ) percent ) ( of ( our electricity ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN As) (NP (NP (NNP America) (POS 's)) (ADJP (RBS most) (JJ abundant)) (NN energy) (NN source))) (, ,) (NP (NN coal)) (VP (VBZ is) (ADVP (RB currently)) (VP (VBN used) (S (VP (TO to) (VP (VB generate) (NP (NP (QP (RB nearly) (CD 60)) (NN percent)) (PP (IN of) (NP (PRP$ our) (NN electricity))))))))) (. .)))
As America's most abundant energy source, coal is currently used to generate nearly 60 percent of our electricity.
(ROOT (S (NP (NNP Coal)) (VP (VBZ is) (NP (NP (DT the) (NN source)) (PP (IN of) (NP (JJS most) (NN electricity))))) (. .)))