In which of the following practices is the waste produced from one process used as a nutrient for another process?

$A$ 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?

The Government of India has introduced a concept to work closely with local communities for the protection and management of forests,which is called:

Provide the full names for the following abbreviations:
$(i)$ $HFC$
$(ii)$ $CFC$

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

Select the appropriate option for $FOAM$.