hello weaam. 
sorry...haha.. act, i also cant remember everything but i do know
they gave a list of information about water
: chlorine kills bacteria in water
: water in house hold contains mineral ions.
cant remember the 3rd one.but im sure its correct!
but wat im not sure about is the forth one.
: filtration is used to remove soluble impurities from water.
is the last one right?
i think the third one was: Water is used in industry for cooling

But i picked 1,2,3 cuz 4 is just dumb

you cant filter something thats dissolved! xD