( It ( ( ( s also ) ( known ( that ( ( when ( fat ( drops ( on ( ( ( hot coals ) or ) ( a ( heating element ) ) ) ) ) ) ) ( , ( chemicals ( called ( ( PAHs ( -LRB- ( ( polycyclic ( aromatic hydrocarbons ) ) -RRB- ) ) ) form ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ s) (ADVP (RB also)) (VP (VBN known) (SBAR (IN that) (S (SBAR (WHADVP (WRB when)) (S (NP (NN fat)) (VP (VBZ drops) (PP (IN on) (NP (NP (JJ hot) (NNS coals)) (CC or) (NP (DT a) (NN heating) (NN element))))))) (, ,) (NP (NNS chemicals)) (VP (VBD called) (SBAR (S (NP (NP (NNP PAHs)) (PRN (-LRB- -LRB-) (NP (JJ polycyclic) (JJ aromatic) (NNS hydrocarbons)) (-RRB- -RRB-))) (VP (VBP form))))))))) (. .)))
It s also known that when fat drops on hot coals or a heating element, chemicals called PAHs (polycyclic aromatic hydrocarbons) form.
(ROOT (S (NP (PRP We)) (VP (VBP call) (NP (NP (DT the) (JJ solid) (NN form)) (PP (IN of) (NP (JJ hydrocarbons) (NN coal))))) (. .)))