( ( ( ( Sulfur Trioxide ) ( -LRB- ( SO3 -RRB- ) ) ) 2 ) . )
(ROOT (NP (NP (NP (NNP Sulfur) (NNP Trioxide)) (PRN (-LRB- -LRB-) (NP (NNP SO3)) (-RRB- -RRB-))) (ADJP (CD 2)) (. .)))
Sulfur Trioxide (SO3) 2.
(ROOT (S (NP (NNP Sulfur)) (VP (MD can) (VP (VB combine) (PP (IN with) (NP (NN oxygen))) (S (VP (TO to) (VP (VB produce) (NP (NN sulfur) (NN trioxide))))))) (. .)))