List any four human activities responsible for the pollution of river water.

What are fossil fuels? How are they formed?

List three reasons to justify the need to manage the available resources carefully.

We should use coal and petroleum judiciously. Why? State any four reasons.

It is important to make small check dams across the flooded gullies because they:

(i) hold water for irrigation

(ii) hold water and prevent soil erosion

(iii) recharge groundwater

(iv) hold water permanently