Aryan invasions, seasonal floods, earthquakes, rivers changing courses, and a decline in trade were all possible factors that led to the fall of what civilization? mesopotamiaindus valleymycenaeanegyptian

What was zheng he’s most important accomplishment? zheng he spread chinese ideas and brought wealth to china from his travels. zheng he commanded an impressive fleet of ships. zheng he sailed the indian ocean and around africa. zheng he conquered lands as far away as africa to increase the dynasty’s power.