The $Chipko$ movement started from $........$.

Which are the primary constituents of photochemical smog?

Which of the following statements is incorrect regarding $DDT$?

Consider the following reasons for the massive fish mortality observed in a lake near a village within a few days:
$(1)$ Excessive use of urea and phosphate fertilizers in nearby crops.
$(2)$ Spraying of $DDT$ using aircraft.
$(3)$ The lake water turned green and foul-smelling.
$(4)$ Initial decrease in phytoplankton in the lake leads to a maximum decrease in photosynthesis.
Which of the above reasons are responsible for the massive fish mortality?

Which of the following is $NOT$ present in photochemical smog?

Match the following columns:

Column-$I$	Column-$II$
$(a)$. Ozone thickness	$(i)$. $UV$ rays
$(b)$. $CFC$	$(ii)$. Refrigerator
$(c)$. $El$ Nino effect	$(iii)$. Temperature increase
$(d)$. Skin cancer	$(iv)$. Dobson unit