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There is a large floodplain in the lower basin where the Euphrates , Tigris , and Karun rivers converge to create the Mesopotamian Marshes , which includes permanent lakes , marshes , and riparian forest .
 Euphrates, Tigris, Karun, Mesopotamian Marshes
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Euphrates, Tigris, Karun, Mesopotamian Marshes