Question: What 1970 American born tennis player won the 1990 ATP Tour World Championships – Singles?
Sentence (from "1998 ATP Tour World Championships"): The singles event took place at the EXPO 2000 Tennis Dome in Hanover, Germany, from 24 November through 29 November 1998, and the doubles event at the Hartford Civic Center in Hartford, Connecticut, United States, from 18 November through 22 November 1998.
Relevant evidence: No