Final answer:
Common materials used in the manufacture of incendiary devices include roadway flares, gasoline or motor oil, and glass containers.
Step-by-step explanation:
In the manufacture of incendiary devices, common materials used include roadway flares, gasoline or motor oil, and glass containers. Roadway flares contain a flammable substance that emits light and heat when ignited. Gasoline and motor oil are highly flammable liquids that can be used as accelerants in incendiary devices. Glass containers can be used to hold and disperse these flammable materials.