Question

Fireworks twinkle bright colors when _________ __________ reacts with oxygen

Answer 1

Fireworks twinkle bright colors when gunpowder and "stars" reacts with oxygen. (These stars hold fuel, an oxidizing agent, a binder and metal salts or metal oxides) [This information is found at https://www.livescience.com/32675-how-do-fireworks-get-their-colors.html if you'd like to go read more] :)