MISSING LINK CXCVI

Each trio of words 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. Door..........Order..........Swipe
2. Call..........Drop..........Poor
3. Bob..........Duck..........Lobster
4. Dash..........Spring..........Running
5. Glow..........Ring..........Earth
6. Inner..........Wild..........Brain
7. Hard..........Show..........Test
8. Mail..........Work..........Money
9. Cat..........Cake..........Cross
10. Soil..........Heavy..........Secret

Answers:

1. Side
2. Kinds of boxes
3. Tail
4. Board
5. Worm
6. Child
7. Case
8. Order
9. Walk
10. Top