( ( The meteorites ) ( ( ( ( have magnetism ) , ) ( with ( ( higher ( specific gravity ) ) ( than ( common rocks ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS meteorites)) (VP (VBP have) (NP (NN magnetism)) (, ,) (PP (IN with) (NP (NP (JJR higher) (JJ specific) (NN gravity)) (PP (IN than) (NP (JJ common) (NNS rocks)))))) (. .)))
The meteorites have magnetism, with higher specific gravity than common rocks.
(ROOT (S (NP (NNP Gravity) (CC and) (NNP magnetism)) (VP (VBP are) (NP (DT both) (JJ common) (NNS forces))) (. .)))
Gravity and magnetism are both common forces.