MISSING LINK C

Each trio of word below shares a Missing Link - that is, its members have something in common, obvious or not. For example, RIVERS, NOSES, & VIOLINS can all have BRIDGES.

1. Feet..........Line..........Tire
2. Soil..........Spin..........Billing
3. Rock..........False..........Bell
4. Cow..........Door..........School
5. Box..........Paper..........Bar
6. Pen..........Pocket..........Paring
7. Needle..........Potato..........Storm
8.Weight..........Hanger..........Tiger
9. Age..........Fish..........Ware
10. Asia..........Palatine..........Indigo

Answers:

1. Things that can be flat
2. Top
3. Bottom
4. Kind of bells
5. Sand
6. Kinds of knives
7. Things with eyes that can't see
8. Paper
9. Stone
10. One of seven (Continents, Hills of Rome, Colors of the rainbow)