Terracing helps in soil conservation in

The limiting factor in nutrification of soil is ------

  What is known as black gold?

___________ are very important for the development and growth of industries.

Which fuel is used to run steam engines and factories?

Inexhaustable non conventional source of energy is ------

Natural resources are divided into ____________.

The exhaustible resources are also called __________ resources.

_____________ resources are being used in the present.