( ( ( One set ) ( of hydrocarbons ) ) ( ( is ( ( volatile ( organic compounds ) ) ( -LRB- ( VOCs -RRB- ) ) ) ) . ) )
(ROOT (S (NP (NP (CD One) (NN set)) (PP (IN of) (NP (NNS hydrocarbons)))) (VP (VBZ is) (NP (NP (JJ volatile) (JJ organic) (NNS compounds)) (PRN (-LRB- -LRB-) (NP (NNP VOCs)) (-RRB- -RRB-)))) (. .)))
One set of hydrocarbons is volatile organic compounds (VOCs).
(ROOT (S (NP (DT A) (NN lipid)) (VP (VBZ is) (NP (NP (CD one)) (PP (IN of) (NP (NP (DT a) (ADJP (RB highly) (JJ diverse)) (NN group)) (PP (IN of) (NP (NP (NNS compounds)) (VP (VBN made) (PRT (RP up)) (ADVP (RB mostly))))) (PP (IN of) (NP (NNS hydrocarbons))))))) (. .)))