* * * Similarity of three energy substances

1, all fossil energy. Coal, oil and natural gas are all formed by biological remains and organic matter after long-term compression and high temperature in geological process.

2. Both are non-renewable energy sources. Because it takes millions of years for them to form, their reserves are limited and non-renewable, and once they are exhausted, they cannot be produced again.

3. They are all important substances in the energy field. Coal, oil and natural gas are the most important energy substances in the world and the main energy sources in the fields of industry, transportation and family.