State the two forms in which energy is mainly utilised in our homes.

Name any two elements that are used in fabricating solar cells.

What do you mean by 'ocean thermal energy'? How can electricity be generated from this energy?

There are about $50$ teachers in a school and most of them come to school by their own cars. Many of the teachers come from the same place but everyone prefers to come to school by his/her own car.
Answer the following questions based on the above information:
$(a)$ Do you think that their practice of commuting to school is environmental-friendly? Give one suggestion. Justify your answer.
$(b)$ In what other two ways can we become environmental-friendly?

What steps would you suggest to minimise environmental pollution caused by the burning of fossil fuels?

Give two uses of coke.