Table: railway_concessions
Columns: concessionaire
fa_division_s
gauge
length_km
takeover_date

Question: What was the guage of the concessionaire ferrosur roca?
SQL: SELECT "gauge" FROM railway_concessions WHERE "concessionaire" = 'ferrosur roca'

Question: Which FA Division has a length of 2704 km?
SQL: SELECT "fa_division_s" FROM railway_concessions WHERE "length_km" = 2704

Question: What is the takeover date of the FA division mitre?
SQL: SELECT "takeover_date" FROM railway_concessions WHERE "fa_division_s" = 'mitre'