Apart of a machine or device that can be replaced by another, identical part

Thomas jefferson was important in the revolutionary era because a) he wrote much of the declaration of independence. b) he was elected the president of the continental congress. c) his philosophies were used in the influential pamphlet common sense. reactivate d) his leadership and moral stand lead to the colonies to fight for the abolition of slavery.

Contrast the ways that frederick douglass and satchel paige to achieve positive changes for african americans.

What new weapon made allied leaders worry about the cost of invading the japanese mainland?