Table: steelers_1977_season
Columns: week
date
opponent
time_et
tv
result
record
game_site

Question: Name the opponent for week 12
SQL: SELECT "opponent" FROM steelers_1977_season WHERE "week" = 12

Question: Name the number of date for shea stadium
SQL: SELECT COUNT("date") FROM steelers_1977_season WHERE "game_site" = 'Shea Stadium'

Question: Name the opponent for astrodome
SQL: SELECT "opponent" FROM steelers_1977_season WHERE "game_site" = 'Astrodome'