Sprinkler and saw: what they have in common

1. Step 1. Sprinkler — has part — Valve. A glass-bulb valve.
2. Step 2. Valve — is part of — Internal combustion engine. Valves let in the mixture and let out the gases.
3. Step 3. Internal combustion engine — is part of — Chainsaw. A two-stroke engine.
4. Step 4. Chainsaw — evolved from — Saw. A mechanized saw.

Open Evothings