Final answer:
Classic civilizations developed advanced urban planning, complex governments, and sophisticated art unlike the simpler structures of early river valley civilizations.
Step-by-step explanation:
Classic civilizations developed sophisticated forms of government, art, and urban planning, where early river valley civilizations had less complex structures and governance. Classic civilizations such as those in Mesopotamia, Egypt, the Indus Valley, and China, witnessed intense developments that included centralization of power, advanced urban planning, and significant advancements in art and culture. These civilizations were supported by agricultural surplus, which facilitated the rise of social hierarchies, craft specialization and monumental architecture, different from the less stratified early river valley societie