The periodic change in temperature in the Pacific Ocean is known as .............

Where did the Chipko Movement take place?

In the town of Arcata,the local people,in collaboration with biologists from $...........$,developed an integrated wastewater treatment process within a natural system.

Which one of the following is the correct expanded form of the acronym?

Match the following columns:

Column-$I$	Column-$II$
$(a)$ Haryana	$(1)$ Ozone hole
$(b)$ Chernobyl	$(2)$ Integrated organic farming
$(c)$ Garhwal	$(3)$ Radioactive waste leakage
$(d)$ Antarctica region	$(4)$ Chipko movement

The figure shows the biomagnification of $DDT$ in an aquatic food chain. What could be the concentration of $DDT$ in $P$,$Q$,and $R$ respectively?