Level 1. ROB, BAR, BOAR, OAR
Level 2. ART, RAT, ALT, ALTAR
Level 3. RIM, IRON, MINOR, NORM
Level 4. RUG, OUR, HUG, ROUGH, HOUR
Level 5. SEA, JAM, SAME, JAMES, SEAM
Level 6. LAX, AIL, AXIAL, AXIL
Level 7. TIE, USE, SET, ITS, SIT, SUIT, SITE, SUITE
Level 8. LANE, GALE, ANGEL, GLEAN, ANGLE
