Loudspeaker and glasses: what they have in common
- Step 1. Loudspeaker — is part of — Television set. Sound.
- Step 2. Television set — evolved into — Flat-screen TV. The picture tube was replaced by a panel.
- Step 3. Flat-screen TV — has part — Liquid-crystal display. An LCD panel.
- Step 4. Liquid-crystal display — has part — Polarizing filter. Polarizers.
- Step 5. Polarizing filter — is part of — Sunglasses. Polarized glasses.
- Step 6. Sunglasses — evolved from — Glasses. Glasses with dark lenses.