0 • A • B • C • D • E • F • G • H • I • J • K • L • M • N • O • P • Q • R • S • T • U • V • W • X • Y • Z
1: Active solar heating system 2: Soil 3: Community 4: Human 5: Water 6: Lead 7: Environment 8: Feeder 9: Condition 10: Process 11: Range 12: Carbon 13: Contamination 14: Atom 15: Current 16: Plant 17: Electricity 18: Animal 19: Ecosystem 20: Development (As of 15:15)