The percentage of $C{O}_{2}CO\_2$ in the atmosphere is

Oxygen is returned to the atmosphere mainly by

Which of the following is a greenhouse gas?

Montreal protocol substances on

The main source of CFCs ……………

Montreal protocol signed by 24 countries in the year ……………

Copenhagen meeting on revise of montreal protocol was held in the year ……………

The ozone hole is observed here

These crops increase soil fertility

Symbiotic bacteria that fixes the nitrogen is ……………