ABCDEFGHIJKLMNOPQRSTUVWYZ

1. obey2. object3. objective4. observe5. obsess6. obsolete7. obvious8. occasionally9. occur10. odd11. of12. off13. offer14. office15. officer16. official17. often18. oil19. old20. on21. once22. one23. only24. open25. operate26. operation27. opinion28. opponent29. opportunity30. optimize31. option32. or33. order34. organization35. other36. out37. outside38. outweigh39. over40. overwhelm41. own42. owner