Assembly line and headphones: what they have in common
- Step 1. Assembly line — uses — Conveyor belt. The product moves between stations on a conveyor.
- Step 2. Conveyor belt — is made of — Leather. The first belts were leather.
- Step 3. Leather — is material for — Bit and bridle. A bridle is leather straps.
- Step 4. Bit and bridle — has part — Headband. Straps on the head.
- Step 5. Headband — is part of — Headphones. A band that presses the cups.