Wooden core and elevator: what they have in common

1. Step 1. Wooden core — is part of — Snowboard. The springy core of the board.
2. Step 2. Snowboard — uses — Friction. It glides over snow.
3. Step 3. Friction — is used in — Pile. A pile is held by friction with the ground.
4. Step 4. Pile — is part of — Foundation. A pile foundation.
5. Step 5. Foundation — is part of — Skyscraper. A deep foundation.
6. Step 6. Skyscraper — has part — Elevator. A skyscraper is impossible without a lift.

Open Evothings