( ( By analogy ) ( , ( ( ( ( ( ( readily biodegradable ) ( organic compounds ) ) , ) ( such ( as ( fuel hydrocarbons ) ) ) ) , ) ( ( could ( be ( included ( in ( this group ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN By) (NP (NN analogy))) (, ,) (NP (NP (ADJP (RB readily) (JJ biodegradable)) (JJ organic) (NNS compounds)) (, ,) (PP (JJ such) (IN as) (NP (NN fuel) (NNS hydrocarbons))) (, ,)) (VP (MD could) (VP (VB be) (VP (VBN included) (PP (IN in) (NP (DT this) (NN group)))))) (. .)))
By analogy, readily biodegradable organic compounds, such as fuel hydrocarbons, could be included in this group.
(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)))))) (. .)))