( So ( ( polar molecules ) ( ( attract ( each other ) ) . ) ) )
(ROOT (S (IN So) (NP (JJ polar) (NNS molecules)) (VP (VBP attract) (NP (DT each) (JJ other))) (. .)))
So polar molecules attract each other.
(ROOT (S (PP (VBN Compared) (PP (IN with) (NP (NP (DT the) (NNS molecules)) (PP (IN of) (NP (JJ many) (JJ other) (NNS substances)))))) (, ,) (NP (NP (NNS molecules)) (PP (IN of) (NP (NN water)))) (VP (VBP are) (ADVP (RB strongly)) (VP (VBN attracted) (PP (TO to) (NP (DT each) (JJ other))))) (. .)))