VI. Read and choose the best answer to fill in each blank.

Humans store energy in ___(1)___ bodies, the earth stores the sun’s energy. The sun’s energy is stored in coal, natural gas, water and wind. Coal, oil, and natural gas are called fossil fuels. We use the energy in these fossil fuels to ___(2)___ electricity. We use electricity in many different ways. We light and heat our homes, schools and businesses using electricity, and to run computers, refrigerators, washing machines, and air conditioners. Our cars and planes run ___(3)___ gasoline, which comes from oil. By the year 2013, most of the energy we use comes from fossil fuels. ___(4)___, fossil fuels are non-renewable sources of energy. They cannot be used over and over again. This means that one day they will run out! Luckily, there are some renewable energy sources we can use. Unlike non-renewable fossil fuels, they will not run out. Three forms of renewable fuels are solar (coming from the sun) energy, water energy and wind energy. All these renewable energy sources are ___(5)___ for us because they will not run out, so we need to get better and better at using them.