Read the passage, and then choose the best answer.
Almost all our energy comes from oil, coal, and natural gas. We call them fossil fuels. The earth’s fossil fuels are running out. What will happen when there is no oil, coal and gas on the earth?
Scientists are trying to find and use other alternative sources of energy. We can use energy from the sun, the wind, and the water.
Solar energy is unlimited. The sun supplies all the energy used to grow plants, to evaporate water for the rain, and to maintain the temperature of the planet. All are necessary for human life. If we are able to collect solar energy, we will be sure to have this abundant source of power.