Plants and animals come, and plants and animals go, but our sun keeps right on working. It heats up the remains (ick) and helps the dead matter to decay. This makes food for other plants (and animals that eat those plants) which grow, then die, repeating the process. But not all of the remains are absorbed by other plants. What’s left sinks into the earth, becomes covered with sand, mud, dirt, and rock, then gets pretty squashed from all the pressure (which makes it heat up). Over millions of years that matter becomes oil, coal, and gas. Or if you look at it another way, all that oil and gas we burn was (at one time) plants, trees, and dinosaurs! Imagine a stegosaurus sticking its head out the tailpipe of your car…
