Grenade and knife: what they have in common

1. Step 1. Grenade — uses — Gunpowder. An explosive.
2. Step 2. Gunpowder — is used in — Fire lance. A gunpowder charge.
3. Step 3. Fire lance — evolved from — Spear. The fire lance was a spear with a tube of gunpowder — the first step to firearms.
4. Step 4. Spear — has part — Stone tool. Early spearheads were made of stone.
5. Step 5. Stone tool — evolved into — Knife. The first knives were stone flakes.

Open Evothings