Hint: Words that end in 'b'
The answer to this puzzle is:
1. PROVERB
2. DISTURB
3. SUBURB
4. ADVERB
5. CLIMB
6. LAB
7. SCRUB
8. THUMB
9. WOMB
10. KNOB
11. LIMB
12. TOMB
2. DISTURB
3. SUBURB
4. ADVERB
5. CLIMB
6. LAB
7. SCRUB
8. THUMB
9. WOMB
10. KNOB
11. LIMB
12. TOMB