( ( Note ( that ( ( ( dark ( matter ( and ( ordinary matter ) ) ) ) ( -LRB- ( ( in ( ( the form ) ( of ( ( hydrogen ( and ( helium gas ) ) ) ( at ( this time ) ) ) ) ) ) -RRB- ) ) ) ( separate ( at ( this time ) ) ) ) ) ) . )
(ROOT (S (VP (NN Note) (SBAR (IN that) (S (NP (NP (JJ dark) (NN matter) (CC and) (JJ ordinary) (NN matter)) (PRN (-LRB- -LRB-) (PP (IN in) (NP (NP (DT the) (NN form)) (PP (IN of) (NP (NP (NN hydrogen) (CC and) (NN helium) (NN gas)) (PP (IN at) (NP (DT this) (NN time))))))) (-RRB- -RRB-))) (VP (VBP separate) (PP (IN at) (NP (DT this) (NN time))))))) (. .)))
Note that dark matter and ordinary matter (in the form of hydrogen and helium gas at this time) separate at this time.
(ROOT (S (NP (NNP Hydrogen)) (VP (VBZ is) (PP (IN in) (NP (NP (NN gas) (NN form)) (PP (IN at) (NP (NN room) (NN temperature)))))) (. .)))