Steel blade and car: what they have in common

1. Step 1. Steel blade — is part of — Knife. A blade with a cutting edge.
2. Step 2. Knife — is part of — Meat grinder. A cross-shaped blade.
3. Step 3. Meat grinder — has part — Crank. A handle.
4. Step 4. Crank — evolved into — Starter motor. It replaced the starting crank.
5. Step 5. Starter motor — uses — Car battery. Power.
6. Step 6. Car battery — is part of — Car. A battery.

Open Evothings