( ( Sulfur trioxide ) ( ( can ( be ( ( prepared ( in ( the laboratory ) ) ) ( by ( ( the ( two-stage pyrolysis ) ) ( of ( sodium bisulfate ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Sulfur) (NNP trioxide)) (VP (MD can) (VP (VB be) (VP (VBN prepared) (PP (IN in) (NP (DT the) (NN laboratory))) (PP (IN by) (NP (NP (DT the) (JJ two-stage) (NNS pyrolysis)) (PP (IN of) (NP (NN sodium) (NN bisulfate)))))))) (. .)))
Sulfur trioxide can be prepared in the laboratory by the two-stage pyrolysis of sodium bisulfate.
(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))))))) (. .)))