Fishing was not a major economic activity in ancient Mesopotamia because the region is located far from the sea.

Grain was the primary form of currency in ancient Egypt because it was a staple food and could be easily stored and transported.

Mining was not a major economic activity in ancient Greece because the region lacked significant mineral resources.

Gold was the primary form of currency in ancient Rome because it was a valuable metal that was easy to store and transport.

Navigation was not a major economic activity in ancient China because the region lacked access to major sea routes.

Cowrie shells were the primary form of currency in ancient India because they were widely available and had a consistent value.

Manufacturing was not a major economic activity in ancient Africa because the region lacked the necessary technology and resources.

Cocoa beans were the primary form of currency in ancient America because they were a valuable commodity that was easy to store and transport.

Mining was not a major economic activity in ancient Australia because the region lacked significant mineral resources.

Whale teeth were the primary form of currency in ancient Oceania because they were a valuable commodity that was easy to store and transport.

Fishing was not a major economic activity in ancient Europe because the region lacked access to major fishing grounds.

Rice was the primary form of currency in ancient Asia because it was a staple food that could be easily stored and transported.

Mining was not a major economic activity in ancient North America because the region lacked significant mineral resources.

Coca leaves were the primary form of currency in ancient South America because they were a valuable commodity that was easy to store and transport.

Agriculture was not a major economic activity in ancient Antarctica because the region is too cold and inhospitable for farming.