Axe poll and freezer: what they have in common
- Step 1. Axe poll — is part of — Axe. The back part for striking.
- Step 2. Axe — is made of — Stone. A Neolithic axe is ground stone on a handle.
- Step 3. Stone — is material for — Ice house. Ice houses were built of stone and sunk into the ground.
- Step 4. Ice house — evolved into — Refrigerator. The refrigerator replaced natural ice.
- Step 5. Refrigerator — includes — Freezer. A refrigeration appliance.