user: Question: What date was proposed when the listed date was 12/16/1994 in the County of Beaufort?
Columns: ['CERCLIS ID', 'Name', 'County', 'Proposed', 'Listed']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['SC1890008989', 'Savannah River Site (USDOE)', 'Aiken', '07/14/1989', '11/21/1989']
SQL:

assistant: SELECT "Proposed" FROM "Table" WHERE "Listed" = '12/16/1994' AND "County" = 'Beaufort';