( ( ( ( ( ( ( ( About 20 ) percent ) ( of ( ( the ( world 's ) ) population ) ) ) ( ( lack access ) ( to ( safe ( drinking water ) ) ) ) ) , ) and ) ( ( 50 percent ) ( ( have ( no access ) ) ( to ( a ( sanitation system ) ) ) ) ) ) . )
(ROOT (S (S (NP (NP (QP (RB About) (CD 20)) (NN percent)) (PP (IN of) (NP (NP (DT the) (NN world) (POS 's)) (NN population)))) (VP (VBP lack) (NP (NN access)) (PP (TO to) (NP (JJ safe) (NN drinking) (NN water))))) (, ,) (CC and) (S (NP (CD 50) (NN percent)) (VP (VBP have) (NP (DT no) (NN access)) (PP (TO to) (NP (DT a) (NN sanitation) (NN system))))) (. .)))
About 20 percent of the world's population lack access to safe drinking water, and 50 percent have no access to a sanitation system.
(ROOT (S (NP (NP (QP (IN At) (JJS least) (CD 20)) (NN percent)) (PP (IN of) (NP (NP (DT the) (NN world) (POS 's)) (NNS people)))) (VP (VBP do) (RB not) (VP (VB have) (NP (NP (DT a) (JJ ready) (NN supply)) (PP (IN of) (NP (JJ clean) (NN drinking) (NN water)))))) (. .)))