Think about it. That little boy who's running back into his house, he may have a nice, clean fresh water supply, but he's got dirty hands that he's going to contaminate his water supply with.
Pomyślcie o tym. Ten chłopiec, który biegnie do domu, może ma zapas czystej, świeżej wody, ale ma brudne ręce, którymi skazi ten zapas.