What is Agent Orange?

Concentration of $DDT$ in small fishes is..... (in $, ppm$)

Provide definitions and explanations for the following terms:
$(i)$ Pollution
$(ii)$ Greenhouse effect

Which of the following is associated with biomagnification?

Which of the following statements are correct regarding Eutrophication?
$I-$ Streams entering into a lake introduce nutrients like nitrogen and phosphorus,which encourage the growth of aquatic organisms.
$II-$ As the lake's fertility increases,plant and animal life flourish.
$III-$ Organic remains begin to deposit at the bottom of the lake.
$IV-$ Organic waste materials continue to accumulate in the lake.
$V -$ The lake becomes shallower and warmer.
$VI -$ Cold-water organisms are replaced by warm-water organisms.
$VII -$ Marsh plants take root in the shallows and begin to fill in the original lake basin.

What is the full form of $CPCB$?