( ( ( ( ( ( Only boiling ) , ) or ) ( a ( sophisticated ( filtration system ) ) ) ) , ) ( ( can ( ( ( kill or ) remove ) ( ( human pathogens ) ( such ( as ( ( giardia and ) leptospirosis ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (RB Only) (JJ boiling)) (, ,) (CC or) (NP (DT a) (JJ sophisticated) (NN filtration) (NN system)) (, ,)) (VP (MD can) (VP (VB kill) (CC or) (VB remove) (NP (NP (JJ human) (NNS pathogens)) (PP (JJ such) (IN as) (NP (NN giardia) (CC and) (NNS leptospirosis)))))) (. .)))
Only boiling, or a sophisticated filtration system, can kill or remove human pathogens such as giardia and leptospirosis.
(ROOT (S (NP (NNP Water)) (VP (MD can) (VP (VB be) (VP (VBN boiled) (S (VP (TO to) (VP (VB kill) (NP (NP (NN giardia)) (CC and) (NP (RBS most) (JJ other) (NNS pathogens))))))))) (. .)))