How were the economies of ancient Mesopotamia , Egypt and the Indus Valley similar?

They were all based on the development of agriculture and later trades and crafts.

Explanation:

The oldest civilizations, including this ones were created in the river valleys, where the first permanent settlements were created.

With the development of irrigational systems, the agriculture was introduced as a main source of profit. Of course, later different labors, including certain crafts were introduced, and then a trade between these regions.

answer: (fluidity)is the correct answer.

explanation: because of this characteristic, success on the battlefield depends in large part on the ability to adapt to proactively change events to our advantage as well as to react quickly to constantly changing conditions