Ruthless exploitation and pollution of the environment has increased the magnitude of waste materials,which has disturbed the operations of all important:

Human activities interfere with the carbon cycle. List any two such activities.

For plastic waste,ragpickers used to get $P$ rupees per kilogram. Now,because of Ahmed Khan,they have started receiving $Q$ rupees per kilogram.

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?

Among the $41$ most polluted cities of the world,Delhi ranked

$UV-$rays are non-ionizing type and are lethal due to their inactivation ability of: