jesusfreak0428

Thanx very much.

Ok I don't know if I'm gonna sound dumb, but I am doing my 6th grade science experiement and i need to know what the control is. I am going to test tap, bottled, fountain, and toilet water. I want to see which one has more bacteria and which is more drinkable, i read somewhere that toilet water is just about the same as fountain i want to know. Can somoen tell me what the control is because i cant figure it out