Table: long_tunnels
Columns: name
location
length_in_km_mi
year_completed
line

Question: What year was the Line of Gardermobanen completed?
SQL: SELECT "year_completed" FROM long_tunnels WHERE "line" = 'gardermobanen'

Question: Which line is the Geumjeong tunnel?
SQL: SELECT "line" FROM long_tunnels WHERE "name" = 'geumjeong tunnel'