Question

the search for fossil fuel alternatives continues. why? the combustion of fossil fuels results in pollution in many cities. the world supply of fossil fuels is running out. co2 neutral substances are emitted by the combustion of fossil fuels. the greenhouse effect is reduced by the combustion of fossil fuels.

Explanation:

Fossil - fuel combustion causes pollution and the world's supply is depleting. Fossil - fuel combustion emits CO2 (not CO2 - neutral substances) and increases the greenhouse effect, not reduces it.

Answer:

The combustion of fossil fuels results in pollution in many cities.
The world supply of fossil fuels is running out.