Oil can be applied on the stagnant water to control the spread of malaria.
(a) How does this practice control the spread of malaria.
(b) Give a reason why this practice should be discouraged.

Answer:

a)
-Mosquito larvae or pupa are killed by suffocation, thereby breaking the life cycle of mosquitoes.
b)
-This practice pollutes the environment
-Oil is expensive
-Other aquatic organisms are also killed.
-The practice contaminates water bodies.

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Oil can be applied on the stagnant water to control the spread of malaria.
(a) How does this practice control the spread of malaria.
(b) Give a reason why this practice should be discouraged.