BASIC 1. flame 2. flammable 3. ignite 4. ignition 5. precise 6. precision 7. meter 8. metric 9. microscope 10. microscopic 11. grave 12. gravity 13. grateful 14. gratitude 15. revise 16. revision 17. athlete 18. athletic 19. humane 20. humanity REVIEW 21. fireproof 22. explosion 23. fume 24. rescue 25. prevention CHALLENGE 26. suffice 27. sufficient 28. impede 29. impediment
