At the beginning of the $20^{th}$ century,forests covered about $.....P.....$ of the land in India. By the end of the century,this had shrunk to $.....Q.....$.

The $Chipko$ movement was started for the protection of .........

The concentration of an insecticide in the animals of a species is called:

Read the following statements carefully and select the correct ones.
$I.$ $UV$ rays are essential for the production as well as degradation of ozone gas.
$II.$ Ozone present in the ionosphere acts as a shield absorbing $UV$ radiation coming from the sun.
$III.$ One-fourth of the incoming solar radiation is reflected by the atmospheric gases and clouds,and only half of the incoming solar radiation falls on the earth's surface,heating it. Of this,only a small portion is reflected back.

Which one is not a renewable energy source of natural resources?

Which of the following statements is incorrect?