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Race into Space
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Rachel Carson
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Rainforest Food Chains
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5.4 |
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Rain Forests Inside Out
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6.0 |
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Ranas y otros anfibios (Frogs and Other Amphibians)
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4.0 |
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Rats Around Us
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6.3 |
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Recycle
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Recycling
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4.1 |
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Reducing Your Foodprint: Farming, Cooking, and Eating for a Healthy Planet
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7.1 |
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Reptile Life Cycle
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2.3 |
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Reptiles
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Reptiles de todo tipo (Reptiles of all Kinds)
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3.7 |
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Reptiles of all Kinds
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3.7 |
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Reptiles raros y espeluznantes pero geniales (Creepy But Cool Weird Reptiles)
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Rescue Missions
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5.7 |
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Resources and Conservation
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Respiratory System
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Return to the Moon
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Rhinos
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1.4 |
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Rivers and Lakes
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5.7 |
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Rivers and Lakes Inside Out
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6.3 |
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Rocks and Minerals
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5.8 |
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Rocky Mountains Research Journal
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5.5 |
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Rolling Along: The Wheel and Axle
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4.4 |
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Canada
USA
