Answer:
D
Explanation:
mathematical and calendar system
Drafted and adopted by the Congress in 1777 but not ratified until 1781, it effectively established the U.S. as a collection of 13 sovereign states, each of which had an equal voice in Congress (which became officially known as the Congress of the Confederation) regardless of population.
Im not sure exactly what your looking for but it may be something on the lines of: Historians base interpretations of past events on first hand sources which consist of diaries and writing or recordings of people who were at the event. A long with other sources such as newspapers.
