Which of the following problems is not caused by noise pollution?

Which of the following plants is used for the purification of water?

$A$ : Montreal Protocol suggested the reduction of $ODS$.
$R$ : $A$ landmark international agreement taken in Earth summit held at Rio de Janeiro.

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

In a pond near a village,a large number of fish suddenly die. Which of the following could be the reason for this?
$(a)$ Large amounts of urea and phosphate are used as fertilizers in nearby fields.
$(b)$ $DDT$ was sprayed in the entire area.
$(c)$ The pond water has become green and dirty.
$(d)$ The population of phytoplankton in the pond has decreased,reducing the photosynthetic capacity.
Which two of the above reasons are responsible?

Pesticides with very low biodegradation but strong affinity for fatty tissues are: