Racket frame and fuel cell: what they have in common
- Step 1. Racket frame — is part of — Tennis racket. The frame of the racket head.
- Step 2. Tennis racket — is made of — Carbon fibre. Modern frames.
- Step 3. Carbon fibre — is material for — Hydrogen car. The tanks are carbon fibre.
- Step 4. Hydrogen car — has part — Fuel cell. A fuel cell.