Insole and radio: what they have in common

1. Step 1. Insole — is part of — Footwear. An inner lining.
2. Step 2. Footwear — is made of — Vulcanized rubber. A rubber sole.
3. Step 3. Vulcanized rubber — is material for — Weather balloon. The envelope is rubber or latex.
4. Step 4. Weather balloon — has part — Radio. A radiosonde.

Open Evothings