1. It takes billions of lifetimes for new fossil fuels to form.

2. At the current time, many families are looking for ways to use less energy.

3. We are discussing about the advantages of some energy sources now.

Exercise 6. Fill in the blanks with the correct form of a suitable verb.

1. Last year, we spent a lot of money on heating because it was very cold.
2. The electrician is installing low energy light bulbs in the classrooms at the moment.
3. Our teacher is discussing a video on types of renewable energy sources now.
4. The plumber is checking cracks in the pipes in the bathroom now.
5. Is your father paying the electricity bill last week?
6. What will you do to reduce your carbon footprint?
7. We will walk to school to keep fit and protect the environment.
8. My uncle put new glass in the windows to stop heat escaping tomorrow.
9. We had a test on sources of energy at present.
10. People in developing countries are using energy from the Sun, the wind, and the water to reduce spend these days.