There are many problems in our modern world. One very（ ）serious problem is energy. We get a great （ ） of energy we need from coal, gas, and oil. However, the （ ） of energy which we use is （ ） every year, and we only have enough coal, gas, and oil for the next twenty or thirty years. How will we live （ ） the energy which these things give us? Scientists are looking for （ ） to this problem. They are looking for new （ ） to produce energy. For example, they are working with new ways to （ ） energy from the light and heat of the sun. They are also working with plans which produce energy from （ ） of the oceans. All of the new methods （ ） scientists are finding are still very expensive, but perhaps they will help solve our energy problems （ ） the future.

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