How many persons are added to the Indian population per year?

The main cause of population explosion in the world is:

Give scientific reasons: Population rise is an unavoidable evil.

Which of the following does not help in the control of population growth?

Phenomenal and rapid increase of population in a short period is called

The world population in $1900$ was ........ billion,which increased rapidly to ........ billion in $2000$ and reached ........ billion in $2011$.