( ( For example ) ( , ( ammonia ( ( becomes ( more ( toxic ( as ( pH increases ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN For) (NP (NN example))) (, ,) (NP (NN ammonia)) (VP (VBZ becomes) (ADJP (RBR more) (JJ toxic) (PP (IN as) (NP (NN pH) (NNS increases))))) (. .)))
For example, ammonia becomes more toxic as pH increases.
(ROOT (S (PP (IN As) (NP (NN ph) (NNS increases))) (, ,) (NP (DT a) (NN solution)) (VP (VBZ becomes) (ADJP (RBR more) (JJ basic))) (. .)))