Table: copa_do_brasil_2000
Columns: team_1
agg
team_2
1st_leg
2nd_leg

Question: What was the 1st leg of the match that had an aggregate of 4-3?
SQL: SELECT "1st_leg" FROM copa_do_brasil_2000 WHERE "agg" = '4-3'

Question: What was the 2nd leg fo the match that had a 1st leg of 1-3 and aggregate of 1-6?
SQL: SELECT "2nd_leg" FROM copa_do_brasil_2000 WHERE "1st_leg" = '1-3' AND "agg" = '1-6'