At the beginning of the twentieth century,forests covered about ....... of the land of India. By the end of the century,it shrunk to.......

Arrange the following options in ascending order of their $BOD$ value.
$I.$ Sample of highly polluted pond water.
$II.$ Sample from unpolluted pond water.
$III.$ Distilled water.

$A$ lake near a village suffered heavy mortality of fishes within a few days. Consider the following reasons for this.
$A.$ Lots of urea and phosphate fertilizer were used in the crops in the vicinity.
$B.$ The area was sprayed with $DDT$ by an aircraft.
$C.$ The lake water turned green and stinky.
$D.$ Phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis.
Which two of the above were the main causes of fish mortality in the lake?

What measures, as an individual, would you take to reduce environmental pollution?

Identify the incorrect statement.

The Kyoto Protocol was endorsed at: