43763
It consists of the rivers Irwell and Mersey made navigable to Manchester for seagoing ships leaving the Mersey estuary .
 Irwell, Mersey, Manchester, Mersey
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Irwell, Mersey, Manchester, Mersey