Which substance is used in refrigerators and air conditioners?

Explain some harmful effects of agricultural practices on the environment.

Which of the following is $NOT$ an effect of deforestation?

In a village in Karnataka,people started cultivating crops all around a lake which was always filled with water. They added fertilisers to their fields in order to enhance the yield. Soon they discovered that the waterbody was completely covered with green floating plants and fishes started dying in large numbers. Analyse the situation and give reasons for the excessive growth of plants and the death of fish in the lake.

What were the main reasons behind the "Ganga Action Plan" which was initiated in $1985$? What values can be learnt from such plans?

List two causes of depletion of the ozone layer. Mention any two harmful effects of the depletion of this layer.