<span>Landslides occur when masses of rock, earth, or debris move down a slope. Debris flows, also known as mudslides, are a common type of fast-moving landslide that tends to flow in channels.</span>
The water cycle consists of three major processes: evaporation, condensation, and precipitation. Evaporation is the process of a liquid's surface changing to a gas. In the water cycle, liquid water (in the ocean, lakes, or rivers) evaporates and becomes water vapor.
Why might a post classical civilization want to conquer Egypt and the Nile River Valley? It's fertile land provided the foundation for the first human civilizations and its access to the Persian Gulf and location between Europe, Asia, and Africa made it a center of trade.
