( ( lower ( pH levels ) ) ( ( ( ( indicate ( increasing acidity ) ) , ) ( while ( ( pH levels ) ( ( higher ( than 7 ) ) ( indicate ( ( increasingly basic ) solutions ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJR lower) (NN pH) (NNS levels)) (VP (VBP indicate) (NP (VBG increasing) (NN acidity)) (, ,) (SBAR (IN while) (S (NP (NN pH) (NNS levels)) (VP (ADVP (ADVP (RBR higher)) (PP (IN than) (NP (CD 7)))) (VBP indicate) (NP (ADJP (RB increasingly) (JJ basic)) (NNS solutions)))))) (. .)))
lower pH levels indicate increasing acidity, while pH levels higher than 7 indicate increasingly basic solutions.
(ROOT (S (PP (IN As) (NP (NN ph) (NNS increases))) (, ,) (NP (DT a) (NN solution)) (VP (VBZ becomes) (ADJP (RBR more) (JJ basic))) (. .)))