Underline the subject in each sentence. Then, write S above singular subjects and P above plural subjects. Remember, compound subjects are plural. For years, fossil fuels have been the main source of energy around the world.
Fossil fuels, which include coal, oil, and natural gas, are nonrenewable.
They are not replenished once they have been used.
In contrast, the sun and wind are renewable energy sources.
The sun’s energy is collected through solar panels and converted into electricity.
Solar power can be used to produce electricity without being connected to a grid.
Turbines capture the wind’s energy and convert it into electricity.
To produce energy, turbines require strong and consistent winds.
Other renewable energy sources include hydropower, biomass, and geothermal energy.
Despite some obstacles, renewable energy will play an important role in the future.