What are the main sources of water?

What are the main sources of thermal pollution ?

What are biofertilisers? What are the main sources of biofertilisers? What is biological N_2 fixation? Name two organisms each of which fix nitrogen asymbiotically and symbiotically.

..................and...............are some of the main sources of water on earth.

What are coherent sources ?

What is the main source of energy for earth ?

What are main sources of carbon in nature?

Coal tar is the main source of

What are the main functions of a stem?

What are the main processes of urine formation ?