( Carcinogens ( ( called ( ( ( polynuclear ( aromatic hydrocarbons ) ) ( -LRB- ( PAHs -RRB- ) ) ) ( are ( formed ( when ( fat ( ( drips ( from food ) ) ( onto ( hot ( coals ( or ( lava rocks ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Carcinogens)) (VP (VBD called) (SBAR (S (NP (NP (JJ polynuclear) (JJ aromatic) (NNS hydrocarbons)) (PRN (-LRB- -LRB-) (NP (NNP PAHs)) (-RRB- -RRB-))) (VP (VBP are) (VP (VBN formed) (SBAR (WHADVP (WRB when)) (S (NP (NN fat)) (VP (VBZ drips) (PP (IN from) (NP (NN food))) (PP (IN onto) (NP (JJ hot) (NNS coals) (CC or) (NN lava) (NNS rocks))))))))))) (. .)))
Carcinogens called polynuclear aromatic hydrocarbons(PAHs) are formed when fat drips from food onto hot coals or lava rocks.
(ROOT (S (NP (PRP We)) (VP (VBP call) (NP (NP (DT the) (JJ solid) (NN form)) (PP (IN of) (NP (JJ hydrocarbons) (NN coal))))) (. .)))