Vital Functions--Amphibians

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Across
  1. 2. For _____ they have inner skeletons made of bone.
  2. 5. Their _____ hatch in water.
  3. 6. For _____ their bodies have neither scales nor hair.
  4. 7. _____ means that they live on land and in water.
  5. 8. Their three-chambered hearts allow for _____.
  6. 9. They breathe with _____ when they mature.
Down
  1. 1. _____ is done by laying jelly-coated eggs.
  2. 3. For _____ they breathe with gills when young.
  3. 4. For _____ they use four limbs.