For the best ecological balance,what percentage of the land mass of a country in the plains should be covered with forests (in $, \%$)?

What percentage of forest cover for hills has been recommended by the National Forest Policy $(1988)$ of India (in $;\%$)?

Identify the correct statement regarding Eutrophication.

Which one of the following pairs is mismatched?

Pollution can be controlled by

How many of the following processes result in the release of $CO_2$ into the atmosphere? Burning of wood,forest fires,photosynthesis,combustion of fossil fuels,decomposition of organic matter,volcanic activity.