user: Question: What is the series # when the US air date is 20 July 2012?
Columns: ['Series #', 'Title', 'Directed by', 'Written by', 'France air date', 'Canadian air date', 'US air date']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '"Pilot" "Pilote"', 'John Stead & Duane Clark', 'Gil Grant', '18April2011', '19 April 2011', '29 June 2012']
SQL:

assistant: SELECT "Series #" FROM "Table" WHERE "US air date" = '20 July 2012';