$(a)$ Why are coal and petroleum called fossil fuels?
$(b)$ Name any two elements present in fossil fuels in addition to carbon.

Given below are a few statements related to biodiversity. Pick those that correctly describe the concept of biodiversity.
$(i)$ Biodiversity refers to the different species of flora and fauna present in an area.
$(ii)$ Biodiversity refers to only the flora of a given area.
$(iii)$ Biodiversity is greater in a forest.
$(iv)$ Biodiversity refers to the total number of individuals of a particular species living in an area.

Which of the following dams is constructed in Gujarat?

How did the 'Chipko Andolan' ultimately benefit the local population? Give any two benefits.

The important message conveyed by the 'Chipko Movement' is

Which natural resource is depleting rapidly in the world?