Which one is not a renewable energy source of natural resources?

What is the biological concentration of $DDT$ in the body fat of Indian people?

Which of the following statements is/are correct?
$I.$ Chemical fertilizers cause pollution of water bodies as well as groundwater,besides getting stored in crop plants. Therefore,environmental scientists are pressing for a switch over to organic farming.
$II.$ Organic farming is a form of agriculture that relies on techniques such as crop rotation,green manure,compost,and biological pest control.

The average concentration of $CO_2$ in the atmosphere is

Which of the following problems is not caused by noise pollution?

The quantity of $CO_2$ in the atmosphere is about (in $\%$)