Fanning a fire increases the oxygen near the fire.
Fire needs oxygen to continue burning.
Fanning a fire helps it to continue burning.
What can help a fire to continue burning?

(1) energy
(2) Conifers
(3) Boiling water
(4) Extinguishing it
(5) Fanning it
(6) bamboo
(7) Removing fuel
(8) sweating