Table: tigers_polls_2008
Columns: poll
pre_season
mar_3
may_5
may_12
may_19
may_26
final_poll

Question: Which pre-season has May 5 of 21?
SQL: SELECT "pre_season" FROM tigers_polls_2008 WHERE "may_5" = '21'

Question: Which March 3 has a Poll of baseball america (top 25)?
SQL: SELECT "mar_3" FROM tigers_polls_2008 WHERE "poll" = 'baseball america (top 25)'

Question: Which pre-season has a Mar. 3 of nr, and a Poll of usa today/espn coaches' poll (top 25)?
SQL: SELECT "pre_season" FROM tigers_polls_2008 WHERE "mar_3" = 'nr' AND "poll" = 'usa today/espn coaches'' poll (top 25)'