Which of the following are industrial wastes?
a) fat, detergents
b) smoke and toxic gases
c) fertilizers
d) pesticides
Which of the following is the example of hard water?
a) sea water
b) lake water
c) stream water
d) all of these
In laboratory we can purify water by…………
a) filtration
b) boiling
c) chlorination
d) all of these
Which of the following is the safest way to purify water……….
a) filtration
b) boiling
c) chlorination
d) all of these
We can add liquid house hold bleach to the water in…….
a) filtration
b) boiling
c) chlorination
d) all of these
