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.
Zamyslete se nad tím. Ten malý chlapec který běží zpátky domů, může mít sice čerstvou pitnou vodu, ale má špinavé ruce, takže jimi vodu kontaminuje.