user: Question: What is the date for the ship Afrika, with nationality Great Britain?
Columns: ['Date', 'Ship', 'Nationality', 'Tonnage', 'Fate']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['16 May 1941', 'Llangibby Castle', 'Great Britain', 11951.0, 'Damaged']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Nationality" = 'Great Britain' AND "Ship" = 'Afrika';