( Compounds ( ( called ( hydrocarbons ( contain ( only ( ( hydrogen and ) carbon ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Compounds)) (VP (VBD called) (SBAR (S (NP (NNS hydrocarbons)) (VP (VBP contain) (NP (JJ only) (NN hydrogen) (CC and) (NN carbon)))))) (. .)))
Compounds called hydrocarbons contain only hydrogen and carbon.
(ROOT (S (NP (NP (JJ Hydrocarbons) (NNS compounds)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VP (VBP serve) (PP (IN as) (NP (NNS fuels)))) (CC and) (VP (VBP are) (VP (VBN used) (PP (IN in) (NP (NN manufacturing)))))))) (, ,)) (VP (VBP are) (VP (VBN called) (NP (NP (DT the) (VBG driving) (NN force)) (PP (IN of) (NP (JJ western) (NN civilization)))))) (. .)))