( ( Low ( pH numbers ) ) ( ( indicate ( that ( ( the water ) ( is acidic ) ) ) ) . ) )
(ROOT (S (NP (NNP Low) (NN pH) (NNS numbers)) (VP (VBP indicate) (SBAR (IN that) (S (NP (DT the) (NN water)) (VP (VBZ is) (ADJP (JJ acidic)))))) (. .)))
Low pH numbers indicate that the water is acidic.
(ROOT (S (NP (NNS Acids)) (VP (VBP are) (VP (VBN associated) (PP (IN with) (NP (NP (DT a) (JJ low) (NN number)) (PP (IN on) (NP (DT the) (NN ph) (NN scale))))))) (. .)))