Why is $CNG$ better than diesel?

Select the correct option for 'Ecosan'.

More than $70\; \%$ of the world's freshwater is contained in

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

The second commitment period for the Kyoto Protocol was decided at

Consider the following statements about eutrophication:
$I.$ Eutrophication is the natural ageing of a water body by nutrient enrichment.
$II.$ The accelerated ageing of lakes due to sewage and agricultural and industrial wastes is called cultural or accelerated eutrophication.
$III.$ The plant nutrients responsible for eutrophication are nitrates and phosphates.
$IV.$ Phosphates and nitrates accelerate the growth of algae which utilize oxygen and may deoxygenate the water enough to kill the fish and other aquatic animals.
Which of the statements given above are correct?