( ( The mouth ) ( also ( ( begins ( ( the process ) ( of ( mechanical digestion ) ) ) ) . ) ) )
(ROOT (S (NP (DT The) (NN mouth)) (ADVP (RB also)) (VP (VBZ begins) (NP (NP (DT the) (NN process)) (PP (IN of) (NP (JJ mechanical) (NN digestion))))) (. .)))
The mouth also begins the process of mechanical digestion.
(ROOT (S (NP (NNP Digestion)) (VP (VBZ begins) (PP (IN in) (NP (DT the) (NN mouth)))) (. .)))