useless trivia: What Word Means: A Spelunker?

Questions

tennis - who won the us open in 1989?

1992 - what san francisco 49ers star was listed as the highest paid?

who sang that he was an "okie from muskogee"?

who was the actor who played lt columbo in the series columbo?

what '27 baseball team had a crew of heavy hitters called murderer's row?