Pollution can be controlled by

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

Which of the following is not a conventional source of energy?

$A$ 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?

Write critical notes on the following:
$(a)$ Eutrophication
$(b)$ Biological magnification
$(c)$ Groundwater depletion and ways for its replenishment

Which of the following pairs is correctly matched?