The correct answer to this open question is the following.
Some of the technological and social developments of the Nile River Valley and Mesopotamian civilizations were the following.
In the case of the Nile River civilization, ancient Egyptians were smart people that develop the technology to understand the flooding of the Nile River to grow their crops. They lived in a desert, so the Nile River was the only water source to grow food.
The other technology was in architecture. Egyptians were capable to build impressive pyramids such as the ones in Cairo, Egypt, that today are considered to be one of the seven wonders of ancient times.
In the case of Mesopotamia, the Sumerians are considered the oldest civilization on Earth, They settled in the middle of the Tigris and Euphrates Rivers, in the Middle East, modern-day Iran.
They developed impressive technology to built their Ziggurats, monumental buildings that represented the main part of their cities.
They also were the first ones to apply agriculture techniques to grow crops, understand the flooding of both rivers, developed the cuneiform scripture to write on clay tablets and were the founders of the concept of city-states such as Kisk, Lagash, Uruk, and Ur.
