1. For a long time/ people/ use water/ power machines.
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2. Solar panels/ place/ the roof/ a house/ and/ sun’s energy/ use/ heat water. ........................................................................................................................
3. We/ use energy/ the sun, the wind, and the water.
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4. Many countries/ already using/ solar energy.
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5. The earth’s fossil fuels/ running out.
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6. We/ looking/ cheap, clean, effective source/ energy/ not cause pollution or waste natural resources. ........................................................................................................................
7. Recently/ wind/ use/ generate electricity.
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8. The sun/ supply/ all energy/ used/ grow plants/ evaporate water/ rain/ and/ maintain/ temperature/ planet ........................................................................................................................
9. At present/ most/ our electricity/ come/ use/ coal, gas, oil or nuclear power. ........................................................................................................................
10. Today/ water power/ mostly/ use/ generate electricity.
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11. This power/ could/ provide/ sun.
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12. If we/ able/ collect solar energy/ we/ be sure/ have enough power. ......................................................................................................................
13. Scientists/ try/ find/ other alternative sources/ energy.
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14. One percent/ solar energy/ reach/ earth/ enough/ provide power/ the total population. ........................................................................................................................
15. Viet Nam/ an advanced technology/ solar energy.
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16. The energy/ store/ a number of days.
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17. Car/ use solar energy/ gas/ by the year 2030.
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18. Energy/ wind/ use/ centuries/ move ships, grind grain, pump water/ and/ do other forms/ work. ........................................................................................................................
19. On/ cloudy/ you/ use/ solar energy/ too.
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20. Almost all our energy/ come/ oil/ gas/ natural gas. We/ them/ fossil fuels. ........................................................................................................................