( ( ( ( ( The ( Planet ( Mercury Learn ) ) ) ( all ( about ( the planet ) ) ) ) ( ( Mercury , ) ( the planet ) ) ) ( closest ( to ( the Sun ) ) ) ) . )
(ROOT (NP (NP (DT The) (NNP Planet) (NNP Mercury) (NNP Learn)) (NP (NP (DT all)) (PP (IN about) (NP (DT the) (NN planet)))) (NP (NP (NNP Mercury)) (, ,) (NP (DT the) (NN planet))) (NP (NP (JJS closest)) (PP (TO to) (NP (DT the) (NNP Sun)))) (. .)))
The Planet Mercury Learn all about the planet Mercury, the planet closest to the Sun.
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (ADJP (ADJP (JJS closest)) (PP (TO to) (NP (PRP$ our) (NN sun))))) (. .)))