<span>Countercurrent oxygen exchange I think
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D I would believe since they all make sense
Energy sources are classified as nonrenewable because they do not form or replenish in a short period of time. Renewable energy sources such as solar and wind replenish naturally in a short period of time.
The four major nonrenewable energy sources are
<span>- Crude oil
- Natural gas
- Coal
- Uranium (nuclear energy) </span>
Nonrenewable energy sources come out of the ground as liquids, gases, and solids. We use crude oil to make liquid petroleum products such as gasoline, diesel fuel, and heating oil. Propane and other hydrocarbon gas liquids, such as butane and ethane, are found in natural gas and crude oil.
All fossil fuels are nonrenewable, but not all nonrenewable energy sources are fossil fuels
Coal, crude oil, and natural gas are all considered fossil fuels because they were formed from the buried remains of plants and animals that lived millions of years ago.
Uranium ore, a solid, is mined and converted to a fuel used at nuclear power plants. Uranium is not a fossil fuel, but it is classified as a nonrenewable fuel.
