| 1. Water |
| 2. Air |
| 3. Fire |
| 4. Earth |
A – 33 Elements
| 5. Aardvark |
| 6. Abacus |
| 7. Acid Rain |
| 8. Activated Carbon |
| 9. Active Robot |
| 10. Aerated Water |
| 11. Agricultural Land |
| 12. Airplane |
| 13. Airship |
| 14. Alcohol |
| 15. Algae |
| 16. Alien |
| 17. All-terrain Vehicle |
| 18. Aluminum |
| 19. Amalgam |
| 20. Amber |
| 21. Amino Acids |
| 22. Ammonites |
| 23. Amphibians |
| 24. Ancient Footwear |
| 25. Ancient Skates |
| 26. Animal Fossil |
| 27. Ants |
| 28. Anvil |
| 29. Aquarium |
| 30. Arthropods |
| 31. Ash |
| 32. Assembly Line |
| 33. Astrolabe |
| 34. Atom Battery |
| 35. Atom Bomb |
| 36. Atomic Submarine |
| 37. Automated Factory |
B – 24 Elements
| 38. Bacteria |
| 39. Bakery |
| 40. Ballon |
| 41. Bamboo |
| 42. Banana |
| 43. Bank |
| 44. Bats |
| 45. Bear |
| 46. Beavers |
| 47. Beehive |
| 48. Bees |
| 49. Beetles |
| 50. Benzine |
| 51. Bickford Fuse |
| 52. Birds |
| 53. Black Lead |
| 54. Boat |
| 55. Bones |
| 56. Borehole |
| 57. Brass |
| 58. Bread |
| 59. Brick |
| 60. Bronze |
| 61. Butterflies |