Colour television and voltaic pile: what they have in common

1. Step 1. Colour television — is a kind of — Television. Television.
2. Step 2. Television — uses — Radio. The image is transmitted by radio.
3. Step 3. Radio — includes — Transistor radio. A radio receiver.
4. Step 4. Transistor radio — has part — Dry cell. Batteries.
5. Step 5. Dry cell — evolved from — Voltaic pile. A convenient form of the galvanic cell.

Open Evothings