Which sentences describe disadvantages of burning fossil fuels instead of using hydrogen fuel cells?
burning fossil fuels contributes to climate change.
burning fossil fuels takes place inside expensive fuel cells.
fossil fuels aren’t widely available, but pure hydrogen is.
fossil fuels are nonrenewable.

Burning fossil fuels contributes to climate change.

Fossil fuels are nonrenewable.

Explanation:

The fossil fuels are the nonrenewable sources of energy where as the hydrogen fuel cells are the renewable sources of energy which uses the energy harnessed from the hydrogen ions to generate electricity.

The burning of the fossil fuels to generate thermal energy can produce huge amounts of the poisonous and polluting gases liberated into the atmosphere. But the hydrogen fuel cells does not produce any polluting gas.

Fossil fuels are non- renewable as they cannot be used again after once used. But the hydrogen fuel cells are the renewable source of energy.

the answers would be

the first one and the second one