Social crossword

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Across
  1. 5. banded iron rocks
  2. 7. areas of high heat and cold
  3. 8. first invention of mankind
  4. 10. pleasant and comfortable environment
  5. 12. remains of any organism which existed long ago
Down
  1. 1. Synonym for the word "live"
  2. 2. small land strip connected to two large landmasses
  3. 3. microorganisms evolved in hot springs
  4. 4. formed by soil erosion
  5. 6. synonym for the word "die"
  6. 9. age old stone age
  7. 11. a group of organisms stopped to exist