Consider the following statements:

1.The main source of water pollution is sewage water

2.Microorganisms ultimately cause oxygen depletion in water bodies

3.Cholera is a water-borne disease

A1 and 2

B2 and 3

C1 and 3

D1, 2 and 3 ✓ Correct

Correct answer: (D) 1, 2 and 3

Explanation

All three statements about water pollution and its effects are true.

Statement 1 is right because sewage water is the chief source of water pollution.

Statement 2 is right because microbes decomposing the sewage use up dissolved oxygen.

Statement 3 is right because cholera spreads through contaminated water.

The oxygen loss suffocates fish and other aquatic life.

Falling dissolved oxygen is measured by rising biochemical oxygen demand.

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