( ( ( ( ( One booklet ) , ) ( for example ) ) , ) ( ( was ( about ( ( the dangers ) ( of ( water contamination ) ) ) ) ) . ) )
(ROOT (S (NP (NP (CD One) (NN booklet)) (, ,) (PP (IN for) (NP (NN example))) (, ,)) (VP (VBD was) (PP (IN about) (NP (NP (DT the) (NNS dangers)) (PP (IN of) (NP (NN water) (NN contamination)))))) (. .)))
One booklet,  for example, was about the dangers of water contamination.
(ROOT (S (NP (NP (CD One) (NN example)) (PP (IN of) (NP (NN matter)))) (VP (VBZ is) (NP (NN water))) (. .)))
One example of matter is water.