Final answer:
Our written history covers a small portion of the existence of the Earth. The historical record is more complete in some regions than others. New discoveries and research constantly expand our knowledge of the past.
Step-by-step explanation:
Our written history covers a relatively small portion of the existence of the Earth. If we think of the entire history of the Earth as a 24-hour day, humans would have appeared only during the last minute of that day. However, our knowledge of the distant past comes from historical documents and artifacts that have survived over time.
Civilizations with long-standing and abundant historical documents often have more complete histories. For example, much is known about European history and Chinese history due to their deep roots in the written word. On the other hand, the historical record is less full in Africa and Latin America.
It's important to note that the historical record is always evolving as new discoveries and research provide more insights into the past.