3.which among the following material is considered useful?
A.empty paint cans
B.empty gasoline container
C.vegerable and fruit peeling
D.drained batteries

4.which of the following property of the material is harmful?
a.biodegradable
b.elasticity
c.poisonous
d.conductivity

5.which of the following substances is considered harmful if it is not used properly
a.toothpaste
b.cooking oil
c.vinegar
d.insecticide


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