What are two types of fossil fuels commonly used?

The correct answer highlights two widely recognized fossil fuels: propane and natural gas. These fuels are derived from the remains of ancient organic materials that have decomposed under heat and pressure over millions of years.

Natural gas is predominantly composed of methane and is commonly used for heating, cooking, and electricity generation, serving as a cleaner alternative to other fossil fuels. Propane, while not a fossil fuel in its original form, is often derived during the processing of natural gas and from crude oil refining. It's widely used for heating, hot water, and cooking, especially in areas where natural gas distribution is not available.

In contrast, other options listed do not fit the criteria as closely. Coal and oil are indeed fossil fuels, but they were not selected in the answer, while wood and biomass are renewable resources and not classified as fossil fuels. Uranium is used in nuclear power and does not belong to the fossil fuel category. Therefore, the identification of propane and natural gas as fossil fuels accurately reflects their usage and origin in energy production.