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Among them is 37-year-old Internet entrepreneur William  Ding Lei  once  China  's richest man who was among 10 billionaires who returned to the list after dropping off in past years .
 countries of residence: Ding Lei, China
Given options, please tell me the relationships of all the listed entity pairs.Output format is "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
 Entity Pairs:  Ding Lei, China 
Answer:
 countries of residence: Ding Lei, China