Level 1. LIT, GIT, HIT, HILT, GILT, LIGHT, TIL
Level 2. SOAR, ALSO, SOLAR, ORAL
Level 3. RUB, SUB, BUS, HUB, RUSH, BRUSH
Level 4. INK, FIN, FINK, FINE, KNIFE, KEN
Level 5. THAN, CHAT, CHANT, HANT
Level 6. LET, FLU, LEFT, FUEL, FLUE, FLUTE, ELF
Level 7. ASK, ASH, SACK, CASH, SHACK, HACK
Level 8. TEE, HER, TREE, HERE, THREE, THERE, THE
