The three. R's which can help us to conserve natural resources for long term use are:

The most rapidly dwindling natural resource in the world is :

Which of the following is not a natural resource ?

The main reason for the abundant coliform bacteria in the water of river Ganga is :

The pH of a sample of water collected from a river is found to be in the range of 3.5 to 4.5. The most likely reason for this is the waste being discharged into the river from a :