In common dialogue, the term fossil fuel also includes hydrocarbon-containing natural resources that are not derived from animal or plant sources.

These are sometimes known instead as mineral fuels.

Various geologic, atmospheric and solar processes can influence atmospheric carbon-14 levels.

After the girls make Will leave the moon pool by telling him that he got hit in the head and was dreaming, Bella tells Will that she was having a good fun.

As Will leaves, Bella still seems to have a crush on Will. Bella is still having crush on Will and tries to get close to him, but he's too busy with training.

After saving Rikki from the water tentacle, the girls find Will unconscious.

Rikki wakes him up and Will tells them about his encounter with the tentacle.

Rikki suspects that Bella has a crush on Will and follows her and Will. Still walking around the jungle, Bella and Will tell about their previous lives before attending the South Coast High School on Gold Coast.

On the island, Bella falls into the water and Will goes to find her. Although Bella planned to lose the way to the moon pool, she and Will end up finding the entrance to the cave.

— The heat generated by burning a fossil fuel is surpassed within a few months by the warming caused by the release of its carbon dioxide into the atmosphere, a new study says. — Weaning cars and trucks off of gasoline and diesel made from fossil fuels is a difficult task.

One promising solution involves biodiesel, which comes from natural oils and fats, but it is costly. — Renewable fuels from pyrolysis bio-oil has been created by researchers.

The girls discover to find out that Will is planning to go to Mako Island.

Bella decides to accompany him and plans to keep him and herself lost on the way to the Moon Pool.

The technique hinges on carbon-14, a radioactive isotope of the element that, unlike other more stable forms of carbon, decays away at a steady rate.