( Groundwater ( begins ( as precipitation ) ) )
(ROOT (S (NP (NNP Groundwater)) (VP (VBZ begins) (PP (IN as) (NP (NN precipitation))))))
Groundwater begins as precipitation
(ROOT (S (NP (NNP Groundwater)) (ADVP (RB primarily)) (VP (VBZ comes) (PP (IN from) (NP (NN precipitation)))) (. .)))