For which film did Natalie Portman win the Oscar for Best Actress?

For which film did Kate Winslet win the Oscar for Best Actress? Who won the Oscar for Best Actress for 'The Blind Side'? For which film did Sandra Bullock win the Oscar for Best Actress? Who won the Oscar for Best Actress for 'Black Swan'? Who won the Oscar for Best Actress for 'The Iron Lady'? Who won the Oscar for Best Actress for 'Silver Linings Playbook'? For which film did Jennifer Lawrence win the Oscar for Best Actress? Who won the Oscar for Best Actress for 'Blue Jasmine'?