The land is quite fertile due to seasonal rains, and the rivers and streams flowing from the mountains. Early settlers farmed the land and used timber, metals and stone from the mountains nearby. Southern Mesopotamia is made up of marshy areas and wide, flat, barren plains.
Mesopotamia's rivers (Tigris and Euphrates) are key to their civilization. Because of the rivers Sumerians (Mesopotamia's people) could trade and travel through them. Not to mention just plain drinking water. Another benefit of the rivers was irrigation.
I think it is the first one (shoppers find sushi...). Cultural diffusion refers to the spread of different cultures around the world. Finding Asian food in America definitely shows an example of cultural spread.
