( ( Note ( that ( ( coal ( , ( oil ( and ( natural gas ) ) ) ) ) ( are ( ( primary ( energy sources ) ) ( which ( are ( extracted ( from ( ( the earth ) ( -LRB- ( ( fossil fuels ) -RRB- ) ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (VP (NN Note) (SBAR (IN that) (S (NP (NN coal) (, ,) (NN oil) (CC and) (JJ natural) (NN gas)) (VP (VBP are) (NP (NP (JJ primary) (NN energy) (NNS sources)) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (VP (VBN extracted) (PP (IN from) (NP (NP (DT the) (NN earth)) (PRN (-LRB- -LRB-) (NP (JJ fossil) (NNS fuels)) (-RRB- -RRB-))))))))))))) (. .)))
Note that coal, oil and natural gas are primary energy sources which are extracted from the earth (fossil fuels).
(ROOT (S (NP (NNP Coal)) (VP (MD can) (VP (VB be) (VP (VP (VBN mined) (PP (IN from) (NP (NN earth)))) (CC and) (VP (VBN used) (PP (IN as) (NP (DT an) (NN energy) (NN source))))))) (. .)))