Crude oil and fitness tracker: what they have in common
- Step 1. Crude oil — is material for — Nylon. The raw material is petrochemical.
- Step 2. Nylon — is material for — Airbag. The airbag is nylon.
- Step 3. Airbag — has part — Accelerometer. The crash sensor is an accelerometer.
- Step 4. Accelerometer — is part of — Fitness tracker. A pedometer.