Answer: Coal
Explanation: Natural gas is basically gas that comes from nature so if you use coal it creates natural smoke or gas. Also like fossil fuels create natural gas as well.
The mistakes in the footnote are the following:
1. The number one should be written in a superscript. In an essay's text, content that will be footnoted should be marked with a raised number immediately after the lines or ideas that are being cited. This has to be applied the same way when starting the footnote.
2. Three more line spaces should be added before the footnote. By separating the footnote from the text, we can prevent some problems in the reading flow.
3. There needs to be a period at the end. Like in every case, a final period will indicate that the idea is concluded, so you can immediately move to the next footnote.
Answer:
the three event in the early of history they are
anatomy,
molecular biology,
biogeography,
fossils, &
direct observation.
