Question

Why is water passed through filters made of sand, charcoal, and gravel?

A.
To remove the floc and the salt that is in the water

B.
To increase the water's amount of oxygen

C.
To treat the water so it doesn't react with metal pipes

D.
To remove additional particles from the water

Answer 1

C because the metal pipes can make huge magnetic waves and can destroy anything that can pass through sand and gravel.