Across
- 2. to believe
- 4. circle, wheel
- 5. a warship designed to operate under water
- 7. impossible to believe
- 9. the study of rocks
- 10. an underground electric railroad
- 13. the inner or indoor part of something, especially a building
Down
- 1. ten
- 3. ten years
- 4. one hundred years
- 5. under
- 6. hundred
- 8. the study of
- 11. to do
- 12. the study of living things