( ( Although ( ( ( Mercury and ) Venus ) ( ( -LRB- ( ( for example ) -RRB- ) ) ( ( do not ) ( have moons ) ) ) ) ) ( , ( they ( ( do ( ( exert ( a ( small pull ) ) ) ( ( ( ( on ( one another ) ) , ) and ) ( on ( ( the ( other planets ) ) ( of ( the ( solar system ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Although) (S (NP (NNP Mercury) (CC and) (NNP Venus)) (PRN (-LRB- -LRB-) (PP (IN for) (NP (NN example))) (-RRB- -RRB-)) (VP (VBP do) (RB not) (VP (VB have) (NP (NNS moons)))))) (, ,) (NP (PRP they)) (VP (VBP do) (VP (VB exert) (NP (DT a) (JJ small) (NN pull)) (PP (PP (IN on) (NP (CD one) (DT another))) (, ,) (CC and) (PP (IN on) (NP (NP (DT the) (JJ other) (NNS planets)) (PP (IN of) (NP (DT the) (JJ solar) (NN system)))))))) (. .)))
Although Mercury and Venus (for example) do not have moons, they do exert a small pull on one another, and on the other planets of the solar system.
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (NP (NP (DT the) (JJS smallest) (NN planet)) (PP (IN in) (NP (PRP$ our) (JJ solar) (NN system))))) (. .)))