( ( -LRB- ( c -RRB- ) ) ( ( ( ( ( the closer ) ( ( the Moon ) ( is ( to ( the Earth ) ) ) ) ) ( -LRB- ( d -RRB- ) ) ) ( ( the closer ) ( ( the Moon ) ( ( appears ( to ( the Sun ) ) ) ( in ( the sky ) ) ) ) ) ) . ) )
(ROOT (S (LST (-LRB- -LRB-) (NN c) (-RRB- -RRB-)) (S (X (DT the) (RBR closer)) (NP (DT the) (NNP Moon)) (VP (VBZ is) (PP (TO to) (NP (DT the) (NN Earth))))) (PRN (-LRB- -LRB-) (VP (VB d)) (-RRB- -RRB-)) (S (X (DT the) (RBR closer)) (NP (DT the) (NNP Moon)) (VP (VBZ appears) (PP (TO to) (NP (DT the) (NNP Sun))) (PP (IN in) (NP (DT the) (NN sky))))) (. .)))
(c) the closer the Moon is to the Earth (d) the closer the Moon appears to the Sun in the sky.
(ROOT (S (NP (NP (DT The) (NN sun)) (CC and) (NP (DT the) (NN moon))) (VP (VBP appear) (S (VP (TO to) (VP (VB be) (PP (IN about) (NP (NP (DT the) (JJ same) (NN size)) (PP (IN in) (NP (DT the) (NN sky))))) (SBAR (IN because) (S (NP (DT the) (NN moon)) (VP (VP (VBZ is) (ADJP (JJR smaller)) (PP (IN in) (NP (NN diameter)))) (CC and) (VP (VBZ is) (ADJP (ADJP (JJR closer)) (PP (TO to) (NP (NN earth)))) (PP (IN than) (NP (DT the) (NN sun))))))))))) (. .)))