what did the ancient indus valley, huang, and nile civilization have in common

The ancient Indus Valley, Huang (Yellow River) Valley, and Nile River civilizations shared several common features:

1. River-based Agriculture: All three civilizations developed along major river valleys (Indus River, Huang He/Yellow River, and Nile River), which provided fertile soil for agriculture and sustained their civilizations.

2. Urban Centers: Each civilization had well-planned urban centers with advanced city layouts, architecture, and infrastructure. Examples include Mohenjo-daro in the Indus Valley, Harappa in the Huang He Valley, and cities like Memphis and Thebes in ancient Egypt.

3. Writing Systems: While the writing systems of the Indus Valley (still undeciphered) and the Huang Valley (oracle bone script) are not fully understood, both civilizations had systems of writing. Ancient Egypt had hieroglyphs.

4. Centralized Government and Social Hierarchy: These civilizations generally had centralized forms of government, with rulers and social hierarchies. In Egypt, for instance, there was a pharaoh; in the Indus Valley, there's evidence of some form of central authority.

5. Religious and Cultural Practices: Each civilization had distinct religious beliefs, rituals, and cultural practices. The construction of monumental structures like the pyramids in Egypt and the Great Bath in the Indus Valley reflects their shared cultural and religious significance.

Despite these similarities, it's important to note that each civilization also had unique characteristics and developments.