( ( ( ( ( Most galaxies ) , ) ( including ( dwarf galaxies ) ) ) , ) ( ( form ( ( ( ( in ( association ( with ( dark matter ) ) ) ) or ) out ) ( of ( gas ( containing metals ) ) ) ) ) . ) )
(ROOT (S (NP (NP (JJS Most) (NNS galaxies)) (, ,) (PP (VBG including) (NP (NN dwarf) (NNS galaxies))) (, ,)) (VP (VBP form) (PP (PP (IN in) (NP (NP (NN association)) (PP (IN with) (NP (JJ dark) (NN matter))))) (CC or) (RB out) (PP (IN of) (NP (NP (NN gas)) (VP (VBG containing) (NP (NNS metals))))))) (. .)))
Most galaxies, including dwarf galaxies, form in association with dark matter or out of gas containing metals.
(ROOT (S (NP (DT A) (NN gas)) (VP (VBZ assumes) (NP (NP (DT the) (NN shape)) (PP (IN of) (NP (PRP$ its) (NN container))))) (. .)))