( ( ( Hydraulic fracturing ) ( -LRB- ( ( ( ( ( ( ( ( also hydrofracturing ) , ) hydrofracking ) , ) fracking ) or ) fraccing ) -RRB- ) ) ) ( , ( ( is ( ( a ( well-stimulation technique ) ) ( ( in which ) ( rock ( is ( fractured ( by ( ( a ( ( hydraulically pressurized ) liquid ) ) ( made ( of ( ( ( ( ( water , ) sand ) , ) and ) chemicals ) ) ) ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (NP (JJ Hydraulic) (NN fracturing)) (PRN (-LRB- -LRB-) (S (VP (VP (ADVP (RB also)) (VBG hydrofracturing)) (, ,) (VP (VBG hydrofracking)) (, ,) (VP (VBG fracking)) (CC or) (VP (VBG fraccing)))) (-RRB- -RRB-))) (, ,) (VP (VBZ is) (NP (NP (DT a) (JJ well-stimulation) (NN technique)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (NN rock)) (VP (VBZ is) (ADJP (VBN fractured) (PP (IN by) (NP (NP (DT a) (ADJP (RB hydraulically) (JJ pressurized)) (NN liquid)) (VP (VBN made) (PP (IN of) (NP (NP (NN water)) (, ,) (NP (NN sand)) (, ,) (CC and) (NP (NNS chemicals))))))))))))) (. .)))
Hydraulic fracturing (also hydrofracturing, hydrofracking, fracking or fraccing), is a well-stimulation technique in which rock is fractured by a hydraulically pressurized liquid made of water, sand, and chemicals.
(ROOT (S (NP (NNP Fracking)) (VP (VBZ is) (NP (NP (DT another) (NN term)) (PP (IN for) (NP (JJ hydraulic) (NN fracturing))))) (. .)))