There is one mistake in each sentence. Underline and correct the mistake.
6. What visitors attended the local festival last year? - Hundreds of them.
7. The burning of fossil fuels is harmful for the environment and public health.
8. Solar energy can convert into other forms of energy, such as heat and electricity.
9. Solar power is by far the more popular renewable energy source.
10. One of the ways you can save energy in your home are to use energy saving light bulbs.
what => how many
for => to
convert => be converted
more => most
are => is