The reason they did not use wood or any other types of materials was that they had no other type of building material.How did the Sumerians trade?They could use the two rivers that outlined Sumer ??? the Tigris and the Euphrates.Also see- What importance did animals have in Sumerian daily life?What were some of the crafts that the Sumerians did?The Sumerians were famed for their mosaics made of li