Name the biomass which is still widely used as a source of heat energy in many households of country.

Fill in the following blanks with suitable words:

(a) Biomass is another form in which .......... energy manifests itself.

(b) Tidal waves build up and recede .............. a day.

What is biomass? Give three examples of biomass.

What are the two ways in which cow-dung can be used as a fuel? Which of them is better and why?

How is charcoal prepared? Explain why, charcoal is a better fuel than wood.