


| 14. __E__ subduction zone | A Pieces of the crust that "float" on the mantle. |
| 15. __C__ convection currents | B The only ocean on Earth 250 million years ago. |
| 16. __D__ Pangea | C Movements in a fluid caused by hotter material rising, then cooling and sinking in a circular motion. |
| 17. __A__ Plates | D Supercontinent 250 million years ago |
| 18. __B__Panthalassa | E Area where two plates are colliding. One plate is pushed down under the other plate. |
| 19. __C__Magma | A The northern half of Pangea after it split apart. |
| 20. __E__Continental Drift Theory | B The deepest places on the surface of the Earth. They are located at subduction zones. |
| 21. __D__Mid-ocean ridge | C Molten rock below the surface of the Earth |
| 22. __A__Laurasia | D Place where two plates are separating. These plates are moving in opposite directions making the oceans larger. |
| 23. __B__Trenches | E The idea that the Earth's plates are "floating" on the mantle and have been for millions of years. |
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