Graphite and davy lamp: what they have in common
Step 1.
Graphite
— is a kind of —
Carbon
. A form of carbon.
Step 2.
Carbon
— includes —
Coal
. Mostly carbon.
Step 3.
Coal
— uses —
Coal mine
. Extraction.
Step 4.
Coal mine
— uses —
Davy lamp
. Protection against methane explosions.
Open Evothings