Hello, I read your comment asking if 도시에 is the same as 도시의 and would like to help you out. 도시의 means “of (the/a) city” / “city’s”, since “…의” is possessive. 도시에 means “in (the/a) city”. Both corrections made by the two members are acceptable: 1. 다른 도시에 사는 대학생들과…: with university students “who live in different cities” 2. 다른 도시의 대학생들과…: university students “of different cities”(=different cities’ university students) Hope this helps:)