1. A: What should we use for cooking instead of gas?
   B: We should use biogas for cooking instead of gas.

2. A: What type of energy source is solar?
   B: Solar is a renewable energy source.

3. A: Why can't nuclear power be used popularly?
   B: Nuclear power can't be used popularly because it is dangerous.

4. A: Why do people use solar power?
   B: People use solar power for heating or cooling the house.

5. A: When was Yaly Hydropower Plant constructed?
   B: Yaly Hydropower Plant was constructed in 1993.

6. A: Where will solar panels be placed?
   B: Solar panels will be placed on the roofs of houses and buildings.

7. A: How much did the US spend on energy research in 2015?
   B: The US spent 55 billion on energy research in 2015.

8. A: How many types of renewable energy are there?
   B: There are seven types of renewable energy.