GENERAL KNOWLEDGE

Detailed explanation-1: -Sumerians relied heavily upon trade in precious metals and stones in the most advanced cities.

Detailed explanation-2: -They had the ability to take inventions that had been developed elsewhere and apply them on a much bigger scale. This way they could mass-produce goods such as textiles and pottery that they could then trade with other people.

Detailed explanation-3: -The economy was mainly agricultural. Wealth came from agricultural productivity, although there was some trade with other cities and regions for luxury goods and things not available locally.