user: Question: What is the average number of silver medals for countries with 0 gold and rank under 3?
Columns: ['Rank', 'Nation', 'Gold', 'Silver', 'Bronze', 'Total']
Types: ['real', 'text', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'Italy', 2.0, 0.0, 2.0, 4.0]
SQL:

assistant: SELECT AVG("Silver") FROM "Table" WHERE "Gold" = 0.0 AND "Rank" < 3.0;